「A Tale of a Mechanical Doll」 —One-way Mission— (「機械人形の話」 ("Kikai Ningyō no Hanashi") —One-way Mission—) is the fourth chapter of the third volume of Kino's Journey —the Beautiful World—.
Kino and Hermes meet an old woman in a dense forest and ask her for directions to a nearby country but the old woman replies that there isn't one and that she must have lost her way in the forest. She suggests spending the night at the home of her master rather than camping out. Kino agrees and the woman leads her to a manor in the woods.
Upon reaching the home the old woman tells Kino and Hermes that she is actually a mechanical doll made to work for humans. After consulting with her master he steps out and invites them to stay in his home. Kino asks him if there is a country nearby, but he says there is none since the forest is so dense. She then asks why he is living in the forest, but the man only replies with the exact same words as before.
At dinnertime Kino it seated in the dining room with the man as well as his wife and son. The old woman brings them dinner and Kino eats delightedly, but the man and his family do not and sit silent and expressionless. Once Kino finishes, the family takes their plates and throws away the food into a secret garbage chute hidden behind a painting on the wall and bring the plates back to the table. When the old woman returns later to ask how was the meal, they respond that it was delicious and she appears very pleased. They then excuse themselves for the evening and Kino is invited to relax at the manor as she pleases, but both Kino and Hermes are curious over the strange behavior of the old woman and the family.
The next morning Kino finds the old woman preparing bread and at the breakfast table the family once again disposes their food once the old woman leaves the room while Kino cleans her plate. The family then departs and the old woman explains the parents work in a town and drop off their son at school along the way.
Mid morning the old woman invites Kino and Hermes to see an interesting sight and lead them to a clearing in the woods with a beautiful lake. She instructs them to peer into the lake and as soon as the sun reaches a certain height in the sky the waters become clear and at the bottom is what appears to be a valley with a town in it. The old woman says that this town can only be seen at certain times of the year and only for a very brief period with certain weather conditions. It appears to be an old town from long ago that met with disaster. Kino thanks her for showing them such an interesting thing and the old woman is very pleased that she was able to be of some service.
As they walk back to the cabin Kino and Hermes whisper to each other that the country seen at the bottom of the lake must be the country they were looking for. But no matter how you looked at it, it was not one that had been there for very long since the buildings were all too modern, but the woman didn't appear to be lying either.
Back at the manor the old woman enjoys lunch with Kino and immediately afterwards she begins cleaning as part of her household duties. However Kino notices that she appears to have a headache and trouble moving about. The old woman says it's probably because her machine body is getting old and perhaps she just needs some grease.
In the afternoon Kino is attempting some maintenence on Hermes but is unable to fix the broken speedometer. Hermes loudly complains but Kino promises to take him to a mechanic since it's beyond her skill to fix. The woman happens to hear the commotion and takes a look. In a jiffy she determines the cause of the problem and fixes Hermes' speedometer as easily and skillfully as a master watchmaker. Hermes is elated but Kino, aware of how exceedingly difficult it is to diagnose can only stare in wonder. The old woman appears very satisfied that she could be of help and begins to prepare dinner, while in private Kino and Hermes wonder who she really is.
At dinnertime Kino cleans her plate while the family tosses their food as usual. She attempts to inquire about the country in the lake but as expected the family has no answers. She thanks them for their hospitality and announces she would be leaving the next day.
The next morning she rises at dawn as usual but unlike the previous days she did not find the old woman baking bread in the kitchen. Kino searches for her to find that she had collapsed in front of her bedroom door and rushes to her aid. The old woman is gasping for air and says that it's finally time to break down. She asks Kino to take her to the family to say goodbye. Kino decides to bring the family instead since the woman can't move, but as soon as she opens the door the family is there already. They enter the room and Kino quickly rushes to wake Hermes and brings him along as well.
As the family stands by the old woman's bedside she asks them if she has been useful, and they immediately reply that she has. Satisfied, the old woman smiles and stops breathing. Kino checks her pulse and confirms that she has passed away. The family agrees and when Kino inquires if she was human after all, they confirm this as well. The family also says that they would give her a burial and invites Kino to assist if she would like.
They all arrive at the clearing beside the lake's shore and the family digs a grave with each of them carrying far more weight than is possible for their stature, including the son. After laying the old woman in her grave they remove two skulls from a bag they brought and place it in the grave with her. The man says that they belong to the woman's husband and son, and after the burial offers to tell the story of the old woman and country at the bottom of the lake. However before they start, the man places his hands on the son's head and removes it entirely, revealing long strands of wires and cords from the next to the head as the son laughs, perfectly unharmed. Kino and Hermes suddenly realize that the entire family are mechanical dolls.
The old woman was a doctor of mechanical engineering in the country at the bottom of the lake. She was a remarkable genius who was able to do anything, but the country was long torn with two races that fought against each other and often resulted in violent outbreaks and bloodshed. The woman's life goal was to help quell the war by producing mechanical dolls that could help humans with their work, thereby easing tensions and allowing smoother negotiation. She worked so long and steadfast that she rarely had time for her own family and missed them terribly. Then one day she finally completed three perfectly functioning mechanical dolls of the highest quality and calibur which was the family. The woman immediately brought them all to her home to celebrate, but when she arrived there she found the building was gone. It had been demolished in a terrorist bombing from the races' feud and she found her husband and son among the rubble. While among the corpses of her family the rubble collapsed on her and she sustained life threatening injuries.
The mechanical dolls rescued her from the debris and treated her injuries at her own research facility, but her brain had been damaged and she was now a different person. Upon waking up the woman looked at the dolls she made and inquired if they were her master's family. The dolls tranquilized her and attempted to treat her further, but each time the woman would wake up and give the same response. Although they saved her life, they couldn't figure out how to return her to normal and so instead they answered 'yes' and pretended that she was a mechanical doll made to serve them. Since she was injured they told her she was still in production and had to wait. During her recovery period the war became more and more intense until the country completely collapsed on itself; people had either completely killed each other or escaped entirely so no one remained. After that, the dolls took her above ground and told her that they would move to a new home where she could work for them. Ever since then the dolls acted as a surrogate family for her in lieu of the one she lost. They would perform regular health checks on her and because of this the woman managed to live a long life well into her eighties. To prevent her from possibly remembering painful things, they also built a dam and completely submerged the country, though they didn't expect that the water would become clear enough to make it visible at times.
Having all the mysteries now explained Kino thanks the dolls for their story and hospitality and begins packing to leave. The dolls however quickly beseech her to make use of them. Since they were made to serve humans, they needed another human to have purpose. They had served their creator thus far by being her family but now that she had passed away they needed new purpose.
Unfortunately Kino has no need for the dolls and declines their offer. They beseech her over and over to make use of them in some way, as workers, friends, family or enemies, they could be anything she needed but Kino bluntly states she does not need anyone except herself.Eventually the dolls come to the realization that they are now obsolete and they walk themselves off the edge of the cliff and sank into the city at the bottom of the lake.
see novel summary; adaptation faithfully identical to novel