「全く見た事のないものと出会う時、人間は人間ではいられない。」
西暦2599年──。火星のテラフォーミングが進行し、その地表は一面の苔とある生物で覆われていた。そして、選ばれし15人の若者達は重要任務の遂行を期待され、有人宇宙船『バグズ2号』に搭乗し、火星へと向かう。かの地で彼らを待つ、想定外の進化を遂げた生物の正体とは…!?
“When you encounter something you have never seen before, you cannot remain human.”
A.D. 2599. Terraforming of Mars is progressing, and the surface is covered with moss and a certain creature. The 15 selected young people are expected to carry out an important mission, board the manned spacecraft Bugs 2, and head to Mars. What is the identity of the creature that has evolved beyond their expectations and is waiting for them there?