The Witness on the Roof

Glancing at her more closely, he noticed dark stains on her white gown. Horror-struck, he bent over her for a moment, and realised that it was unmistakably a corpse.

Little Polly Spencer liked to visit her hiding place up on the London rooftops, to escape a scolding or worse from her stepmother. Peeping through a studio window, she sees what looks like a burglary. But signs of robbery are merely a cover for murder - and the young figure on the roof seemingly the only witness to the crime.
Polly is sent to live with her well-born mother's family, her secret kept from the police. More than a decade later, she has become Lady Warchester, the wife of a wealthy titled man—yet, in a world utterly removed from her childhood, she will finally face the pale-faced killer she glimpsed through the window all those years ago. And the danger of having seen too much is about to become acute...
The Witness on the Roof (1925) is a classic of early golden age crime fiction. This new edition, the first in over eighty years, features an introduction by crime fiction historian Curtis Evans.
"Miss Haynes has a sense of character; her people are vivid and not the usual puppets of detective fiction." New Statesman