 Harold Van Wick just loves inventing gadgets, and his house is filled with them. But investing in new technology is sending his family s electronics company deep into the red. His mother-in-law decides to remove him as head of the company and threatens to show her daughter evidence of his infidelity. He thinks his inventions will help him commit the perfect murder. Later it seems his mother-in-law was shot by an intruder while he was at an art gallery. But clever gadgets aren t enough to fool the rumpled, redoubtable Lt. Columbo.