Rather like the Hitch Hiker's Guide, but without the humour. A plot which only works by a series of unlikely coincidences.
It begins with the girl going swimming and apparently disappearing, her husband searches the sea in the area for half an hour and then goes running off on a wild goose chase thinking she's been abducted. Switch back to the beach, and lo and behold the girl swims up and finds hubby gone, immediately assumes he's left her to search for his missing finger (don't ask!) on Earth and runs off in that direction. It is topped off with a weak, contrived ending, that does not answer the question did they ultimately save the universe or not? Several apparently important characters are introduced in the last few chapters, but exactly who they are and their actions are unexplained.