The Dark Between the Stars — Jane Blackmore

This is heaven, Sorrel thought, when she became companion to old Mrs. Vane. No one knew her here, or knew about the mysterious death of her husband. And now there was David, Mrs. Vane's son, and for the first time in her life Sorrel was in love. -- But the house was not a refuge after all - after Mrs. Vane was murdered. It was a nightmare repeated, and Sorrel feared that knowledge of the past would tar her with the brush of guilt.

But someone in the house did know, someone who demanded a price for silence that Sorrel would not, could not, pay.

She would simply run away, disappear - but there was David, and she knew that flight would be an admission of guilt in the eyes of the man she loved . . .