Thoroughly astonishing book from Josephine Tey. It's a 1920s detective mystery starring the enigmatic Inspector Grant (a big old closet case if ever there was one).
A Hollywood starlet is found dead on a Cornish beach, and a manhunt ensues for a man who may have been her lover.
While Inspector Grant loyally starts to track down his chief suspect, he's occasionally aided, and more often thwarted by the Chief Constable's daughter, a determined gal who's in the Guides, drives a loud motor car badly, and learned to fight dirty from a boxing champ....
She is, in short, the best Doctor Who companion, ever, and proceeds to run rings around the hapless Grant for a good 250 joyous pages.
Hurrah for Joesphine Tey - who is terribly clever, died young, and left all her money to the National Trust.