Scotland Yard is after a homicidal maniac called The Blue Hand, which is what he uses to kill his victims.

When the Paris airport management is informed by telephone that there is a time bomb on board a Canadian Atlantic Airways plane to Montréal, they initially believe it is a bad joke. But the caller answers again. Inspector Bignon gets involved...

Detective Heinz Ebelings car breaks down with a broken windshield and a defective fuel pump on the way to Frankfurt. On the way to the next village, Ebeling witnesses a murder and other crimes, which he tries to solve.