Famous private detective Tip O'Neil is summoned by telegram to the estate of old friend Paul Harding, but finds the telegram was sent by Paul's attractive secretary, Amy Hutchins. Paul admits his dog was shot by extortionists to show they mean business, and shows Tip some threatening notes they sent. That night, Paul's ward, Corinne, is kidnapped by two gangsters and her driver is found dead the next morning. The kidnappers contact Tip demanding $200,000, which is delivered according to instructions. Awaiting the return of Corrine, Tip learns her fiancé, Gene Leland, is an ex-convict, and he also investigates why a thug, Maratti, was found prowling around the grounds, and why Paul's brother-in-law, Jim Glenray, was seen leaving the estate late the night before. And when the chauffeur is murdered with Amy's gun as he was about to confess some complicity, Tip has to piece together various clues to pinpoint the culprits.