The Frighteners (not to be confused with the film of the same title) is a 1989 spy novel by Donald Hamilton, continuing the adventures of his creation, assassin Matt Helm.

Helm is assigned to impersonate a rich oil baron in order to track down a shipment of weapons before it can be used to overthrow the Mexican government.

Head of the agency borrowing Matt Helm, a man called Somerset, wants Matt to go into Mexico and help trace a shipment of illegal arms, supposedly being smuggled to be supplied to Mexican revolutionaries by the said millionaire Horace Hosmer Cody.

In the beginning of the novel, Cody is arrested by Somerset's people and Helm takes his place with a make up job that he thinks will fool no one and it doesn't.

Almost all of the story takes place in Mexico where Matt once again runs into his old ally Ramon Solana-Ruiz of the Mexican security.