The IMF has 16 hours to find a nuclear bomb placed by an extortionist, Dr. Cooper, in one of seven Pacific Coast cities and find Cooper's associates in charge of disarming the bomb. The IMF track Cooper to a cafe and fake a radio broadcast announcing his demands will be met - then Jim and Mimi break in as convicts and take Cooper and the others hostage. The IMF eventually ""let"" Cooper call his associate Rogers to disarm the bomb but Cooper's wife Adele kills Rogers when she fears the plan has gone awry. When Rogers' death is announced on the radio, a frustrated Cooper convinces Jim and Mimi to take him to the bomb (beneath City Hall) which he shuts off with seconds to spare - the IMF take him into custody.

Jérôme Cooper, un scientifique aux idées extrémistes, menace de larguer une bombe atomique sur une grande ville américaine si plusieurs membres du gouvernement ne sont pas remplacés par des hommes qui partagent ses points de vue. Phelps et Mimi tenteront de détruire l'endroit où est stockée la bombe.