Special Branch and MI5 alert AXE to the fact that Sir Malcolm Drake has recently visited Hanoi and has secretly met senior Chinese Government officials in Beijing.
Carter reconnoitres Drake's vast estate on the western coast of Puerto Rico which is guarded by mercenaries led by former Australian Army sergeant-major, Harry Crabtree.
Returning to San Juan, Carter meets Hawk who has learned from his CIA and MI5 counterparts that someone in the Caribbean is hiring petty criminals and that five convicted murderers in Cuba have been allowed to escape.
A secret message encoded in the book Monica Drake gave to Carter reveals a plot to assassinate the President of the United States and implicating Cuba as the instigator.
While the US fights Cuba, China will invade North Vietnam to prevent Ho Chi Minh from surrendering to the US.
The billion dollars' worth of gold is to pay Malcolm Drake to arrange the assassination and to establish his own country by invading Haiti.
Drake reveals that the plan to assassinate the President of the United States was merely a ploy to get the gold from China to support his invasion of Haiti.
The PT heads into the Mona Passage where it meets up with a tramp steamer transporting the gold bullion from China.