Jerry Cotton: The Trap Snaps Shut at Midnight (1966)

Third Jerry Cotton Adaption. A big shipment of Nitroglycerine, enough to make a shambles of New York, mysteriously vanishes! It's a race between agent Jerry Cotton and the underworld to see who can find the deadly explosive first. To complicate things further, the nitro must be found before a torrid heat wave causes it to blow much of the city sky high.