Mrs. Marrable, an elderly widow, hid a ferocious animal cunning behind her mask of tart respectability. Her main interest was gardening, which fitted in admirably with her business of murder. She kept a line of handsome poplars at the edge of her country lawn, and at intervals Mrs. Marrable had occasion to order a hole dug for another tree. These occasions usually arose when there was a body to dispose of, a body that had been a hired companion, one without relatives but with a tidy nest egg which enabled Mrs. Marrable to enjoy her little luxuries.