In a frozen, post-apocalyptic world, Mei leaves Shanghai after receiving a radio broadcast from other survivors in Huangshan. In the snow, she meets Xenya, a vampire who offers her shelter in a mobile bunker.
The two travel south together. Between meals, repairs and conversations in their moving home, Mei gradually grows closer to Xenya. Told from Mei's perspective, Lastrip follows their journey and the relationship that develops along the way.