Two lifelong friends – designated by the numbers 1203 and 1204 – grow up with the shared dream of becoming cosmonauts. They easily pass the many physical tests they take during their cosmonaut training, and they even attempt to simulate the feel of flying through space by bouncing on their beds. They are ultimately selected for the next mission, with 1203 being launched solo and 1204 standing by as the reserve cosmonaut. The launch at first goes smoothly, but communication with the ship is soon lost; it is implied that 1203 dies in the vacuum of space. Inconsolable with grief, 1204 refuses to take off his spacesuit; an X-ray shows him curled up in a fetal position in the torso. Eventually, medical staff saw his helmet off, but find the suit empty except for a photo of the two friends in their spacesuits. They then look up to see a hole shaped like 1204's body in the ceiling above his bed, and 1204 is shown drifting suitless through space, where the still-suited 1203 grabs him by the arm.
