The latest outing for Detective Chief Supt. Ben Spence is a little less police-procedural, a little more old-time-whodunit, than his other recent episodes. The setting is Marlby Manor, where rich, elderly, tolerant Lady Dinnister (whose household includes a gambling butler and a cook who poses nude on the side) is planning to leave her fortune to grand-kids Alee and Elizabeth, The heirs are a greedy lot, however--especially debt-ridden Elizabeth and crass husband Vernon, who try to persuade Lady D. to sell the Manor and move to smaller quarters. And when this scheme is foiled by Lady D.'s forthright, rather tactless companion Emily Fosdyke, she (Emily) is soon found dead of arsenic poisoning. Murder, of course--but was the poison really intended for Lady D. herself? So: enter Chief Supt. Spence, who'll use one of those awfully implausible murderer-catching traps to snare the culprit. Aside from that hackneyed touch, however: comfortable, mildly beguiling entertainment in the traditional style.