An astronaut flies to a new planet with a robot. The astronaut misses home very much. The robot is responsible for collecting data from the planet and helping the astronaut in sending messages to his son. But ...太空人與機器人一同飛往外星執行任務。太空人拿著自己與兒子的合照瞄了一眼，愛子之情只好銘記在心。機器人每天按程序往返飛船與外星基地之間，蒐集數據樣本；它按指令回覆太空人的兒子，許下諾言：他們會回家。飛船的升空動力不足，機器人耗盡自己的能量，啟動飛船的自動導航模式飛返地球。太空人原來已經……
