Special agent Matt Helm is called upon to prevent an international catastrophe when a billion dollars in gold intended to bolster the British economy is hijacked in Denmark by a crime ring headed by Count Contini.  The Count's former mistress, Lola Medina, offers to help Matt, but she is killed by a bomb-rigged Scotch bottle before she can talk.  Also eager to assist is Freya Carlson, an enthusiastic but bumbling young woman who has been assigned by the Danish tourist office to help Matt.

Matt and Freya gain entry to the Count's mansion by posing as journalists, but they are forced to flee when they are attacked by members of the gang.  Two of the Count's seductive aides, Linka Karensky and Yu-Rang, then separately attempt to lure Matt to his death, but their plans for an intimate but lethal rendezvous are interrupted by the timely, though clumsy, intervention of Freya.

Eventually, Matt's superior, MacDonald, arrives on the scene.  After revealing that Freya is actually a secret agent, he forces a showdown with the Count.  As a result, Linka is killed in an ambush set for Matt and Freya, while MacDonald succeeds only in getting himself wounded.  Matt and Freya then trail Contini to his chateau and utilize numerous gadgets to outwit their opponents.

After Yu-Rang has been killed in one of several explosions, Matt and Freya make a getaway by means of Matt's portable, folding mini-copter and board the train on which the Count is taking the gold to Luxembourg.  During the melee that follows, the Count falls to his death through a trap door.

With the gold saved, the villains foiled, and the train controls set on automatic, the mishap-prone Freya sets out to seduce the willing Matt.