Murderers' Row (1966)

The handsome top agent Matt dies a tragic death in his bath tub - the women mourn about the loss. However it's just faked for his latest top-secret mission: He shall find Dr. Solaris, inventor of the Helium laser beam, powerful enough to destroy a whole continent. It seems Dr. Solaris has been kidnapped by a criminal organization. The trace leads to the Cote D'Azur.