Carroll John Daly 
The Strange Case of Iva Grey [EPUB ebook] 
(Black Mask)

Wacky as a loon—that was Connelly's first impression of the Grey gal when she walked into his office and offered him a retainer for protecting her from the man she loved. And who could blame him? It was a million-buck check she presented to that hard-boiled investigator and the signature it bore was simply "The Man in the Moon!"