The story centers on the couple Franklin and Irene York, who discovered a capsule/secret chamber buried under their backyard many years ago, which can be used to travel to a strange and desolate planet. Since then, they have carefully guarded this secret, but when a mysterious young man enters their lives, the York family's peaceful life is quickly disrupted, and the mysterious capsule/secret chamber that they thought they knew very well is much more complicated than they imagined.