When a woman is found dead in her home, all signs point to suicide. However, Captain Stottlemeyer has reason to believe otherwise and calls in for Monk's opinion. Monk agrees that this was definitely a murder, and after a little investigating, he believes the killer to be an astronaut. The only problem with Monk's lead suspect is that he wasn't even on the planet at the time of the murder; he was out in space. Monk, still certain that he's the guy, must figure out how to prove to everyone that it was in fact him, despite his airtight alibi.