Blackrock. The Dark Between Stars, #3

There's something lurking in the caverns under Blackrock.The pirate settlement of Blackrock depends for oxygen on the vast algae vats set into caverns deep under the surface of the rocky moon. But recently, vat workers have been turning up dead. And not natural deaths-they're shooting their own friends, walking off 30-metre drops, stepping out into the path of a ghost to be torn to pieces, driven mad with terror.
The overworked doctors at the small hospital can't find any trace of what's causing it, but everyone who's come back alive swears there's something down in the caverns beneath Blackrock. Something alive. Something unnatural. Something that wants them dead. Jem and the rest of Puppy's small medical crew answered the pirates' distress call, and they've promised they'd do whatever they could to help.
And Jem has spent thirteen years running from her own terror and guilt. But deep in the caverns below Blackrock, she and the rest of the crew will have to face up to a terror they can't run from, unless they're willing to let the entire settlement of Blackrock die. And Puppy's crew could never do that. Set in the world of The Devil and the Dark, Blackrock is the third book in R. M. Olson's gripping space-horror series, The Dark Between Stars.