An extended version of the second season's first episode, which is under the same title.

In Muv-Luv Alternative, Takeru wakes up three years after the end of Muv-Luv Unlimited to find himself back in his room. Although he first thinks that everything that had happened to him was a dream, he soon feels that something is wrong, and leaves the house to find that he has been sent back in time to the beginning of the events in Unlimited. Unwilling to accept something like Alternative V, he decides to help professor Kouzuki to complete Alternative IV and save mankind. (Source: Wikipedia)

Chuuta Kokonose is an orphan who lives with his aunt. For as long as he can remember, he's had a voice in his head, but other than that he's a normal boy—right until the day when a strange-looking thing follows him home and teleports him to a place filled with more fantastic creatures. It's a space police station, and Rein Brickke, the Chief of Solar System Department, tells him that he's been chosen by the computer as a possible candidate to join the police force. Misuzu Sonokata, a girl from Chuuta's school with an angelic face and ill temper who turns out to be one of Rein Brickke's subordinates, doesn't think him suitable for such a job. Chuuta, who was shocked at first, decides to take the aptitude test after being urged by the voice in his head and to prove Misuzu wrong.

Far in the future, the human beings were pushed into the deep underground world called Labyrinth and they are living shoulder-to-shoulder. The Labyrinth has several colonies with severe settings such as one having an insanely high temperature, while another is full of gold and silver. Among those, in a colony of Pinyin, resides a curious nine-year-old girl named Memempuu and her father Gaganbar. As "workers" aiming for survival, they live with the lowest profession of riding a working robot to dig ore. One day, Memempuu pestered Gaganbar, a cave examiner who makes maps of the internal part of Labyrinth, to go travel together with her to find her mother. As a "marker," Gaganbar holds the most dangerous yet attractive profession. One step outside the colony is already deemed to be a dangerous area and meeting a huge mysterious creature that loiters the cave, one's chance of living will be cut down to five percent. Since it is a dangerous racket to explore the unknown world, the map they hold is valuable and can be sold at a high price. However, is the price for their curiosity higher? What could be the cruel truth that is hidden among them? What awaits at the end of the test? In this travel story between a father and a daughter surrounds adventure with family love. (Source: MAL News)