The Humanx Commonwealth: Book Eight.
The mission to planet Quofum to investigate unknown flora and fauna is supposed to be a quickie for Captain Boylan and his crew.
The first surprise is that Quofum, which seems to regularly slip in and out of existence, is actually there when they arrive. The second surprise is Quofum's wild biodiversity: the planet is not logical, ordered or rational. But the real shock comes when the crew members not only find a killer in their midst but discover that their spaceship is missing - along with all means of communication.
Of course, the marooned team-mates know nothing about the Great Evil racing toward the galaxy, or about Flinx, the only person with half a chance to stop it. Nor do they know that Quofum could play a crucial role in defeating the all devouring monster from beyond.