I'd never read Jim Hines before but I was in a mood for something light, so I picked this up expecting some kind of zany, "Guardians of the Galaxy" witty space romp.
What I got was a five star SF read. This is a funny, fast-paced, witty and original novel that also has a clever and quite serious plot.
The story takes place in a universe where most humans have been turned feral by a zombie plague from which 10,000 or so have been rescued by an alien race who now use them as a military force. The post-plague humans are hard to kill, aggressive and loyal. For the aliens, it's a great deal.
The janitors of the title humans who keep the warship clean and plumbing functioning, albeit that their leader, nicknamed mops, is occasionally consulted by the humans in battle command because she has good strategic insights and keeps a cool head.
When the warship gets caught in a trap that kills the alien officers and turns most of the humans feral again, it's left to Mops and her crew to find out what happened and save the universe, or at least humanity.
The pace is fast. The humour is irresistible. Yet this is not a shallow book. The universe-building is robust and complex. The characters, including the alien characters, are believable and engaging. The plot stands up against more mainstream SF and contains a big, skillfully revealed, secret. Best of all, Mops turns out to be a giant amongst humans: a natural leader, a shrewd tactician, an insatiable reader (Jane Austin's and Mary Shelley's works have survived the holocaust), quietly brave and always witty.
What more could I want?
The book works as a standalone novel but sets up the sequel, "Terminal Uprising" beautifully. It comes out in February 2019 and I'd have already pre-ordered it except Amazon want to gouge me for a you-cannot-be-serious $18.42 for the privilege. I figure time is on my side.
Amazon pricing policy to one side, I highly recommend this book to anyone with who loves SF and has a sense of humour.