'C' is for Corpse, by Sue Grafton

(pb; 1986: third book in the Kinsey Millhone mysteries)

From the back cover:

"Kinsey meets him in the local gym. Bobby Callahan is a scarred young man struggling back to life after a car forced his Porsche over the edge of a canyon, battering his body and muddling his memory. All he remembers is that someone, for some reason, tried to kill him.

"Desperate for clues about his own pat life and certain he is being stalked, he asks Kinsey to protect him. Kinsey can't resist the brave kid -- and neither can the killer. Three days later Bobby is dead. Kinsey Millhone never welshed on a deal. She'd been hired to stop a killing. Now she'd find the killer."

Review:

Kinsey has two problems this time. The first is finding out who killed the nice young man (Bobby Callahan) who hired her to find his murder-minded stalker; the second is figuring out what exactly is going on with Lila Sams, the ill-at-ease, weird, sixty-something girlfriend of Henry Pitts, Kinsey's crossword-writing landlord. It seems that the possibly-shady Sams has leached herself onto the charming, smitten Pitts, while alienating everyone else around them -- including Kinsey.

The killer isn't so easily sussed out this time, at least not until the last third, and Sams, her character semi-transparent, is an alarming character/element in the third Kinsey mystery.

As thrilling, taut and unputdownable as the previous Kinsey mysteries (the last one being 'B' is for Burglar ), it's another hit for Grafton.

Followed by 'D' is for Deadbeat.