Another trip to the altar for Hugh (Bulldog) Drummond and Phyllis Clavering is averted when, at a pre-wedding gathering at the Clavering estate in Switzerland, a Swiss detective guarding the wedding gifts is murdered and an artificial diamond is stolen. Another trip to the altar for Hugh (Bulldog) Drummond and Phyllis Clavering is averted when, at a pre-wedding gathering at the Clavering estate in Switzerland, a Swiss detective guarding the wedding gifts is murdered and an artificial diamond is stolen.