H.M. and the Masked Death. There were only two guests at the Stranhope mansion. Vincent James was a weekend perennial - charming and a little thick. Nick Wood, the other guest, was undoubtedly attractive, but it was odd that no one knew anything else about him. It was odd too that the fabulous Stanhope paintings had been moved from the burglarproof gallery to the main floor. And the Stanhope daughters had the jitters. Then, late at night, came a frightful noise - and a masked man was found on the dining room floor, stabbed by a long, thin fruit knife. That was how things stood when crusty, uproarious, irrepressible H.M. arrived on the scene. From then on things moved as only H.M. can make them move - at break-neck speed - with mystery, humor, terror, and a hair-raising climax that revealed the master hand of a killer.