居心何在

居 = 古 + 尸 : Mnemonic symbol: 寄居蟹, ji4ju1xie4, a hermite crab.

A ghost is haunting Zeus and the hermite crab in front of the space station. While the hermite crab is able to retreat into the cloister it uses as shell, Zeus can only float away in horror.

心 = 乚 + 丶 : Marie Curie (xi) uses a shovel (乚) to dig a hole in front of the encampment ((e)n1). She wants to bury her heart (心). To the side are three petal leaves (丶), with which she wants to cover it afterwards.

何 = 亻 + 可 : Mnemonic symbol (from "carry"): baby sling

何 = 亻 + 可 : In the elevator's kitchen, Rosa Luxemburg picks up the crying baby Hamlet from his bed of nails, puts him in his baby sling and tries to calm him down.

在 = 一 + 亻 + 土 : Zorro (z) and Rosa Luxemburg (亻) exist (在) in the airplane's bathroom (ai4). Rosa is in the middle of balancing a flute (一) on her head and on a pile of clay (土). Zorro uses his rapier to inscribe "Z" into the flute, so as to mark that the pronunciation of "在" begins with "z".