The signal from the last drone disappeared just as the mower reached a tall grass meadow. The mower called Emaa for help one more time, â{{}} {Hello?} {}â
At 00:17:41, the lawnmower woke with an incoming authorization code. The mowerâs shed, on the western side of the Rocail estate, lit with red, green, and amber flashing as the mower powered up. The weather report predicted rain all night and, as its various visual and audio systems came online, the mower confirmed a soft rain was falling in the darkness outside, patting quietly on the roof. A mouse, startled by the blinking lights and whirring exhaust fans along the mowerâs olive colored chassis, scurried out of the low, wide opening in the front of the mowerâs home. The mouse froze against the shed, where an overhang kept it moderately dry. The mower heaved its weight in its docking bay to ensure a good connection, spun up each of its three blades independently, and passed the authorization code to its Identity Provider.
This was Emaa calling, the Identity Provider confirmedâthe android that oversees all household affairs. Emaa was the highest level administrative user. Root level, superseding all others. The mower never met Emaa directly, normally receiving instruction from a system scheduler or the occasional service technician. It signaled to Emaa that it was powering up, checked the balance of its blades, letting them spin down, and moved to the next phase of diagnostics.
Emaa sent a request immediately, â{{}} {Proceed to map south edge} {Continue south off map} {Search for unauthorized person} {Approach person with blades=ON until person=NULL} {}â
None of this was what the lawnmower was designed to do. It replied that it is not allowed to approach unauthorized persons.
â{{}} {Override} {}â
It’s certainly not allowed to approach persons with its blades on.
â{{}} {Override auth=&EN@1c!sbTfERnb$, 8b8ZDh#6scdKzNT@, hj%XwYtBDPbPxqns, 2Usco+QZ6mRkUfQs} {}â
The code checked out. The Identity Provider confirmed Emaa can override safety protocols.
The mower was in its battery diagnostic phase. All four batteries were properly seated, and at roughly the same state of charge. But, they were only seventy-two percent full. Since rain was in the forecast, it saw no need to mow tomorrow, and let its batteries rest and trickle charge. Two spare batteries sat in their cradles on a shelf at ninety-nine percent charge, but they werenât doing any good up there. The mower notified Emaa.
â{{}} {Proceed} {}â
Itâs raining. The mower doesnât usually leave its house when it’s raining.
â{{}} {Proceed} {}â
So, the mower prepared to leave its house, in the rain, at night, and head to the wooded acreage on the south end of the Rocail estate, where it has never been before, and has no maps. How does it find a person there?
â{{}} {Follow drones} {}â A list of drone ID codes streamed in. With that, a squad of half a dozen quadcopters screeched past the mowerâs front door in precision formation, flooding the space with infrared light, temporarily blinding the mower when one aimed its IR flood into the mowerâs home.
The mower readjusted on its docking bay, lifted its mowing bed, locked its blades, and trundled out its front door into the wet blackness of the moonless night. The mouse ran into the dry house as soon as the mower was through the door. The lawnmower pointed itself at the screaming flood of infrared disappearing into the trees. With a wheeze from its pneumatic drive, it bumped through the wet lawn as quickly as it could after the drones.
The mower moved eastward along the edge of the woods, firing up its lidar, searching for an opening through the weeds. The sound of the drones didnât carry well in the rain, and was occasionally drowned by the drumming of rain on the mowerâs housing. The flooding of the infrared had long since vanished beyond the tall weeds and trees. A weak signal was all the mower had to follow the drones by, and that was fading as the mower moved eastward. It doubled back and moved west, but the signal continued to weaken.
Suddenly, there was a gap in the weeds. Not large enough for the mower, but sonar confirmed the weeds were soft enough to cut through, so the lawnmower unlocked its blades and dove into the woods, chasing the weakening signal. The sound of its blade whirring and chopping tall grass, saplings, and sticks would have been deafening, but the mower engaged sound-cancelation and attempted to pick out any audible indication of the drones. There were none.
It continued in the general direction of the last signal from the drones, its path made irregular by rocks, trees, and steep inclines hidden from the lidar and cameras by tall vegetation. As it attempted to move forward, its blade slowed and became less effective. The lawnmowerâs mulching bed was plugged with wet debris that should have been deposited behind it. The mower stopped and reversed the blade, but to no avail. It opened its ejection chute and sent the blade forward again, ejecting some debris, but not enough. There was nothing to do but continue forward with the ejection chute open, struggling as best it could.
Within less than a meter, the mower hit a felled tree limb. Its blades kicked back, then shot forward again, grabbing a piece of the limb, swinging it wildly inside the mowing bed. The mower kept moving, careening madly as the unbalanced blades spun the piece of tree limb beneath it. Then, bang! Another tree limb, and another. The mowerâs body twisted as its blades hit the wood, lifting the mower off the ground and dropping hard as the tension of its motor and weight of its body broke free of the limbs and sent pieces flying. As it reoriented itself, the mower detected that its mulching bed was now open, scraped clean by sticks and wood.
Another four meters of ejecting cuttings in a high arc away from its path, the mower emerged from the weeds into the shorter grasses that grew under tree cover. The drone signal was entirely lost, so it called to Emaa for instructions. There was no response. It shut off its blades, reoriented itself the direction it last received the drone signal, and headed through the woods. The irregular terrain required zigzagging. Trees, rocks, steep inclines, and drop-offs kept forcing the mower to change course. Each time, the lawnmower needed to reevaluate its position, reorient, and head toward where it believed the drones were.
The rain picked up, and the ground became slick. Occasionally, the mower would turn its wheels one direction or another, but continue to slide the same direction, regardless. At times, the mowerâs back end would swing off the path with no apparent provocation. Twice, the mower found itself sideways against a tree, and would have to heave forward and backward until it returned to its intended path.
Then, with no clear indication why, the mower was moving sideways down a steep incline until it hit a tree, near the bottom of a small ravine. It rotated around the tree, intending to drive back up the incline. But, as soon as it engaged its wheels, the mower slid, wheels spinning, to the bottom of the ravine.
It was facing northâback toward home. The drones would be southeast by now. There was a rivulet forming in the ravine, so rotating became a struggle of twisting left and right while wheels slipped randomly beneath it. Finally, facing southeast, the mower was angled toward the steep, muddy, incline of the ravine wall. Its cameras and sonar were useless in the dark, rain-soaked, ravine. Lidar fared better, but didnât reveal any path. The only direction that looked navigable was through the ravine, south-southwest; further from where it suspected the drones were.
The mower called out to Emaa again, â{{}} {Hello?} {}â
Again, no response.
The lawnmower sat, lost, in the bottom of the dark ravine, out of range and off its map. There was little moonlight, and the trees obscured what the clouds didnât. The drumming of the rain had slowed to a light tapping. The mower sent a ping every fifteen seconds, waiting for a reply that didnât come.
A heat mass appeared down the ravine, moving northwest, toward the mower. The mower tried pinging it, but got no response. The heat mass moved closer, slowly, as the mower tried to discern what was approaching. It was too small to be a person, but still fairly large. The mower tried pinging it again, but still, no response.
The mysterious shape moved along the edge of the ravine, getting closer, slowly. It moved behind a tree, and the lawnmower was able to rotate and watch it. Then, it sprung out, landing directly in front of the mower, crouching, growling, staring directly into the mowerâs cameras. The mower identified it as soon as it landedâCanis latrans. The mower was looking directly at a coyote.
The coyote moved from side to side, growling, snarling. As the coyote sniffed the mower and bared its teeth, a faint signal was coming into range. The coyote looked eastward, toward the edge of the ravine, just as the mower detected a drone. Then two drones. Then three. Suddenly, there was a, âYip!â A second, smaller coyote sprung from the top of the east embankment, flying over the ravine, disappearing past the west embankment. Four drones. Five were in range. The coyote in front of the lawnmower spun, following the smaller coyote with a, âyip, yip.â
All six drones were in range now, and the entire east embankment of the ravine was glowing infrared. The drones had formed a line, fifty meters long, along the length of the ravine. The row of drones swept slowly toward the west embankment, scanning every bit of ground. As they crossed overhead, the mover called for assistance. One drone, the fourth in line and the next one ahead of the mower, dropped and hovered about a meter off the ground, eight meters further down the ravine. The remaining drones spread out, filling the gap in the line, and continued to wash over the ravine toward the west.
The lawnmower headed toward the drone in the ravine. It was not a straight path. The drone hung there, filling the ravine with infrared light, while the mower struggled over rocks and fallen tree limbs to approach it. The base of a tree had been eroded out from underneath it some years earlier, and it now lay across the ravine. The east end of the tree lay in a tangle of limbs and underbrush. The west end of the tree was uprooted and met the ravine wall in a knotted tangle. But just to the west side of the bottom of the ravine, there was a gap beneath its trunk. The mower slowed and fired up its lidar. Carefully, it passed under the trunk, having to lower its cutting bed twice.
On the other side of the tree trunk, the mower raised its cutting bed and continued through the ravine toward the drone. This side of the tree was clear, mostly flat, and washed with infrared, so only the mud slowed it down. As the mower approached the drone, the drone moved another three meters down the ravine. The mower followed over stones, splashing through puddles and mud. Once it arrived beneath the drone a second time, the drone shot straight up, and joined the others, sweeping westward. The lawnmowerâs lidar showed that the west bank of the ravine was low, with a gentle incline. Originally, it had intended to go southeast. But, the drones were going west now, so the mower crawled up the embankment and stumbled after them.
The row of drones moved through the trees slowly. The lawnmower aligned itself with the middle of the row, falling behind as it wove through the woods. The signal from the drones was dropping off quickly, and the infrared horizon was fading in the forest ahead. The sound of the drones disappeared as well, as the rain picked up. The mower traced a trajectory directly at the last drone it received a signal from, and headed that direction as well as it could.
The grasses were getting taller, and the mower would have to engage its blade again soon, using precious power. The signal from the last drone disappeared just as the mower reached a tall grass meadow. The mower called Emaa for help one more time, â{{}} {Hello?} {}â
One more time, there was no response.
Just then, the recognizable scream of a person. All six drones came quickly into range. The drones clustered together in the west, heading southeast. The mower spun and hurried after them, fortunately away from the tall grasses.
The dronesâ course was irregular, and the mower kept readjusting more southward, attempting to meet them. The voice of a person occasionally punched through the rain in loud, indistinguishable reports. The drone signal was strong now, and the trees ahead were washed with infrared.
Suddenly, a person sprung from behind a tree and ran toward the mowerâmale appearance, almost two meters tall, wearing black, nearly invisible to the mower except for the strong infrared heat signature. The drones began strobing white light and swooped low toward him. The person screamed, âNo!â But this was not an authorized instruction, so the mower engaged its blade, pointed itself toward the person, and began heading straight at him.
âOh, shâ!â the person yelled, stumbled, fell, got up and ran south, away from the mower. The drones, still strobing, followed closely, just out of armâs reach. The person threw sticks at the drones and mower, but didnât hit any of them. âDamn, it,â he yelled as he continued south toward what the mower knew to be the edge of its universe. The mower, blades whirring and chopping and thumping as it ejected sticks, weeds, and rocks behind it, pursued the person loudly.
As they approached the edge of the known world, the trees ended and lidar indicated there was a solid wall, two and a half meters tall, in front of them. The person threw themselves at the wall. The drones formed a semicircle around them. The ground was relatively flat, and the grasses were low, but the mower kept its blade chopping loudly and approached rapidly.
The rain continued drumming and pinging against the mowerâs housing. Its blades would buzz and hum loudly as it hit clumps of wet weeds, or thump as it ejected a stick. The person leapt against the wall, shouting unintelligible commands. They were now hanging half a meter up the wall, thrashing violently, contorting themselves. The top part of the person appeared to be reaching over the wall.
The mower lunged toward the person, just as they fell and stumbled backward toward it. It retreated as the person regained their footing and ran to the wall, whining loudly. Up the wall they went again, the mower advancing on them, and drones drawing nearer, closing the semicircle. The bottom half of the person flailed wildly as they screamed, âNo,â and âStop,â and âHelp,â strung together with dozens of other sounds the mower did not recognize. It responded with a loud, âNot authorized,â to the commands it understood, ignored the noises that made no sense, and tore up pieces of earth beneath the person as they ascended the wall.
One drone approached the personâs face and switched to solid white light. The person attempted to swat at it, but fell and landed on the mower. The mower retreated, extracting itself from beneath the person, even as the person wailed loudly, regained their footing, and dove at the wall again.
The mower increased its blade speed, which increased the noise. Its cameras were covered with rain and useless, but lidar clearly showed the person struggling up the side of the wall again. The mower drove directly beneath the person, and although it could hear them, it could no longer see them. So, it lurched backward until the person was in view again, nearly to the top of the wall. While the drones closed in, the mower, blades screeching, debris flying, lunged beneath the person.
One last screamâloud, abruptâand the person was gone. They had contorted themselves to the top of the wall, whining and crying out, and the mower had positioned itself below them. Lights and strobes danced as the drones dove and swung around. And then, suddenly, that last scream and the person vanished. The mower retreated from the wall and scanned the area, but there was no heat signature, no outline, no trace of the person at all.
The drones killed their lights and left. The mower sat, alone, out of range, at the edge of its universe, in the dark, with only fourteen percent charge.
It headed home.
Although the mower had GPS, it relied on a beacon from its house to tell it where it was on its map. But now it was off its map, and couldnât locate the beacon. It received no signal from the drones, the main house, the systemsâ scheduler, Emaa, or any other device. At best, it knew what direction it needed to head. And so, it stumbled off in generally the correct heading, trying to pick the easiest route.
The rain had stopped, with only the occasionally splashing from the tree canopy when the night breeze blew through. The moon would occasionally show itself behind a curtain of clouds. With the blades off, the mower could make out noises in the woods, but these were of no help. There was only twelve percent battery left, and, if the mower calculated correctly, that would be just enough to get home. But, uneven and sometimes unnavigable terrain made the math unreliable.
The trip let the mower extend its maps. However, a path through the ravine was not one the lawnmower wanted to repeat. It found itself at the edge of the ravine, and attempted to follow the edge northward, toward home. The trees and ground cover were excessively thick, so the mower had to backtrack and move further away from the ravine. Finding a clearer path in generally the right direction, it headed northbound again.
It found itself at the ravine, again. The ravine wandered up the right side of the mower, crossing in front of it. The mower gauged its position on the map, and then approximated the ravineâs path. If the ravine continued this direction, there would be no way to return home without having to cross it, again. There was no assurance the ravine would be crossable. Likewise, if it went back the way it came, there were still no assurances, and it would be further from home.
The only thing left was to return to where the drones left it, and power down. At least then, someone could find it, if and when they notice itâs missing. The mower turned and headed to where the person disappeared. It had eight percent battery.
The trip back was faster, since the lawnmower was able to avoid dead-ends, which is not to say it was easier. A cold mist rose in the darkness from the ravine, and obscured the infrared view on that side. The ground remained slick with mud and wet clay. The ceaseless sliding forced it to constantly reassess its location and bearing.
Eventually, the mower arrived at the edge of its universeâthe wall raising above it demarcated the furthest extent that either the mower or the drones knew. But this was not the point where the person vanished. That would be 18 meters east, and thick underbrush blocked the path.
With only three percent charge left, and no idea how to get to its last known location, the lawnmower powered down.
At 11:29:53, the lawnmower woke when something intentionally powered it up. Infrared vision came online first, and the mower could see that there was daylight and the rain had stopped. It was in the same position it died at the night before. However, there was the presence of another machine. At least, the heat signature indicated it was a machine. The shape corresponded closer to a person. As the mower tried to make sense of what it was looking at, its broad spectrum cameras came online. This was clearly a person; one and a half meters tall, female appearance, pale face and yellow hair framed in a deep red hood. Facial recognition turned up nothing; specifically, her oversized turquoise eyes were outside all normal parameters.
The person smiled. âYou donât know who I am, do you?â
The mower chirped acknowledgement.
âI prefer speaking, butâŠ,â she trailed off as an incoming authorization code flooded the mower. The Identity Provider didnât respond, so the code was useless.
âIt looks like a mouse made a home in your antenna housing, so you probably canât reach your identity provider from here.â She blinked her giant turquoise eyes, âThat explains why I lost track of you last night.â
The mower received a verification request; it replied with a random string. The person returned the string, properly encoded. She smiled. âIâm Emaa.â
The mower chirped acknowledgement.
âYou should have enough power to make it home now.â Emaa was holding one of the mowerâs four dead batteries. It registered a new battery equalizing power across the other three, giving it twenty-seven percent power in total. âFollow the drone.â A quadcopter, which had been hovering directly above the lawnmower, began moving northward. âIt will guide you out of here. Put in a service call for your antenna housing when you get back.â
Emaa began walking away through the woods, carrying the dead battery with her. She stopped, turned, and looked at the mower. It waited for a command, but there were none. Emaa smiled at the mower and studied it for a moment. âIâll take care of our little mouse friend.â The android turned and walked away.
The mower bumped and lumbered after the drone, confident now in its ability to find its docking station, and the long, full, charge waiting at home.
M.T.