People of the distant future have taken a rule: human lives are too precious to risk for the exploration of deep space. That's why in the atmosphere of an alien unfriendly planet, beneath the wide crown of the space garden «Ailanthus», lives a race of artificial servants - Artifites.
A young Artifite - explorer, Ein, is tormented by a vague longing. He doesn't know when the expedition began, and why it still can't reach its goal. One thing he knows for sure is that since they're stuck here for a while, he should find himself a girl. And he's got just the right one in mind.
Frequent encounters in the wardroom, lunches together with the whole crew... the task seems a piece of cake. But there are three catches. First, the girl is as cold and unfriendly like cosmic ice. The second one, she's obsessed with exploring abandoned alien ruins, hidden beneath the planet's cloud cover. And the third one, the empty ruins have begun to respond to her.