This episode doesnt have the usually high gag quality I would associate with the show. Mostly because this is the first episode w/o Rimmer a big source for the jokes and skretches.
However, unlike most fans I actually though Kochanski's character worked quite well in the new dynamic. This episode carrys on where Kryton and Kochanski's characters are still at loggerheads because of Krytons fear that she will take Lister away from him. Futhermore, the episode theme is to take the piss out of SF shows where crews have to perform the oh so pointless crawl through the ships crawlspaces to achieve some life or death task.
The main theme of the show is basically a Rite of Passage for Kochanski during the middle act, which is a pointless excericse where she gets to know the crew and her character is expanded upon. Several scenes with her as the primary actor are used to flush out what she is feeling, which as you might expect isnt great at being marooned with this crew.
While Lister's claustrophobia doesnt really spark anything other than an interesting story about Kochanski - and a squeeky gate, which I wont spoil for you here.
Not as funny as previous epiosdes, nothing of consequence happens, but if you want to catch every detail about Kochanski then tune in - otherwise you wont miss much.