Tolefree is visited by Cossor, a K.C. whom he met on an earlier case. Cossor desires that Tolefree should journey to Cornwall and join a house party at Blackabrook, the home of the retired K.C. William Trethewy, and to investigate the theft of a missing necklace. Cossor claims that he is merely anxious to avoid any unwonted unpleasantness that might arise from the revelation of the culprit. But Cossor has deeper fears which he refuses to divulge until Tolefree is on the scene. Not long after Tolefree's arrival, the necklace is returned as mysteriously as it disappeared. But a particularly nasty attempt on Trethewy's life leads Tolefree to realise that his task has now become the more serious one of preventing a murder - before it is too late... Originally published in 1940, this is a vintage murder mystery from the golden age of crime fiction which makes memorable use of real Cornish locations.
Robert Alfred John Walling (11 January 1869, Exeter – 4 September 1949 Plympton) was an English journalist and author of detective novels, who signed his works "R. A. J. Walling".