Murder or suicide? After a disastrous debut in Carnegie Hall, Jan Tusar walked off the concert stage, put down his violin, wrote a note, and put a bullet through his head---in front of witnesses. Then Tusar's violin disappeared and detective Tecumseh Fox knew it had to be murder. Fox had all the suspects on hand, but the clues were leading him nowhere.until a stolen Chinese vase was returned by parcel post and a Park Avenue playboy was poisoned in the company of eight witnesses