Random SF idea: slice-of-life about the locksmith who troubleshoots the door latch mechanisms of all the alien embassies in our solar system.
Knowing when you need the oxygen tank before you go in is an important aspect. As is knowing how much torsion a tentacle can apply to a handle, how much clearance to leave for the vespiform queens that use their ovipositor to stab the hole in the deadbolt, how to drill a lock under a 1000 bar pressure column of Europan under-ice water, and so on.