Anthony Boucher 
Rocket to the Morgue [EPUB ebook] 

A superb mixture of locked room mystery and science fiction classic’A fine craftsman’ Ellery Queen A deadly net of danger tightens around Hilary Foulkes as an unseen enemy makes constant, bizarre attempts on his life. Detective Terry Marshall and his unusual assistant, the inquisitive nun Sister Ursula, work desperately against the clock to break the case – for Foulkes’s luck is due to run out at any moment . . . ROCKET TO THE MORGUE is the novel in which Anthony Boucher’s two interests, crime and SF, collide. As well as being a classic locked-room mystery, it is also considered something of an SF trailblazer, featuring thinly disguised versions of such luminaries of the Southern California science fiction culture of the 1940s as Robert Heinlein and L. Ron Hubbard.