Synopsis: Free-lance assassin Ernemann is in Mexico with orders to kill a certain Mexican general. Mac's agent, code-named Roger, is assigned to take out Ernemann, but is instead killed by U.S. agents working for Andrew Euler. Helm, assigned as a back-up in case anything happens to Roger, takes over the project. He is hampered by other U.S. agents who think he's a traitor, a Mexican secret-agent, Solana-Ruiz, who is one of Ernemann's employers, and Mr. Soo, the Chinese agent who has finally gotten tired of Helm spoiling all his plans and also hires Ernemann to kill Helm. Then there is Roger's sister, Clarissa, who also happens to be the wife of one of the bad guys; she also employed Ernemann--to kill both her husband and ex-lover. By the time Eric gets it all straightened out, a whole bunch of people are dead. The Retaliators earned Donald Hamilton an Edgar Allen Poe Award nomination from the Mystery Writers of America in 1976.

The Players:

• Andrew Euler, a U.S. government administrator, who cannot bear the thought that Mac's outfit is part of the U.S. government and sets out to destroy it. He fails, of course, and winds up in a suicidal psycho ward.
• Clarissa O'Hearn, Roger's sister, and wife of Oscar O'Hearn. She plays a deadly game of revenge and winds up as a rich widow.
• Virginia Dominguez, code-named Norma, one of Mac's people. Assigned to help Matt get Ernemann, she is captured and held as a hostage, but survives.
• Ramon Solana-Ruiz, Mexican agent, who hired Ernemann to kill General Diaz. He is kicked upstairs to an administrative post after the mission and is thankful to leave the super-spook business.
• General Hernando Diaz, the man chosen to be the leader of a new country to be formed in Baha, California. His death put an end to that.
• Ernemann, the assassin, who would have become a rich man if he had succeeded in fulfilling all the contracts he had on people's lives, and lived to collect it. His dreams ended with one shot from Eric's rifle.

Scorecard:
Amorous conquests: This novel is unique. The word "darling" is nowhere to be found. Matt's sexual activities are also somewhat limited on this assignment. He does spend some time in bed with Clarissa, but only to prove to her that sex can be fun. Clarissa calls him "Mr. Helm" or "Matt," but never "darling."

Dead: Who knows? (Roger killed three before he was killed; Euler killed one of his own men; Oscar O'Hearn, killed by Ernemann; Krakowski, Oscar's pilot, killed by an unidentified oriental assassin, who also killed a couple other folks at the same time, including General Diaz. Matt Helm killed two of Solana's men, the unidentified Oriental assassin, and Ernemann.)

Injuries to Matt Helm: While being slapped around by one of the bad guys, he gets his face scratched up a bit by the signet ring the man was wearing, but otherwise, no harm done.

Quote: "Matt, you've taken leave of your senses--"
     I said, "Very good, sir! You obviously have the situation clearly in mind: you've got a senseless maniac heading for the border with a powerful truck, two hostages, a couple of loaded guns, plenty of spare ammo, and a very itchy trigger finger. Your own private senseless maniac, sir. Call me Frankenstein, Junior."
     "I believe," Mac said carefully, "that Frankenstein was the creator, not the monster, Matt."
     "Well, you're the creator, all right, and you know better than anybody what kind of a monster you made. You've used it often enough for your own purposes. Now I'm using me for my purposes, sir. Nobody's making a sitting target of me the way they did Roger. They can get me, but they'll have to take me moving, and I'll be moving fast. And shooting back. Pass the word, sir."
     "Very well. I'll try to convince Mr. Euler that you mean business, but I can't promise that I'll be able to persuade him to let you through."
     I said grimly, "If not, you'd better warn the local undertakers to brace themselves for a rush of business."

Conclusion: Once again Matt helps Mac save his agency from being terminated, which means he will be able to keep working. The book ends with Eric going to pick up Norma, and the two of them spend some time together before Helm goes off to Canada once again in . . .