Crossover Cover: Plutonium Nightmare

This novel features the New Pulp hero the Voice, who is heavily implied to be Secret Agent X's son. I covered the Voice's origin story, "Voice to a New Generation," in a Crossover of the Week post a while ago. At one point, the Voice says, “In the long run the police, as Nero Wolfe once told my Dad, have their legions of experts.” The hero also gives many thanks to Uncle Simon and Willie, his British knife throwing mentors, referring to Simon Templar (alias the Saint) and Willie Garvin (Modesty Blaise's sidekick), respectively. There's also a bonus story included called "The Last Son of Thor," a sequel to Roberts' novella "The Sons of Thor," which was previously the subject of a Crossover Cover post here, in which the Voice encounters the last remnants of the Sons, a German nationalist group that had a run-in with several vigilantes in the late '30s. The hero remembers his Uncle Dick, the father of his best friend Curt Van Loan, telling them about the Sons, and recommending the young boy ask his big Uncle Jim and Uncle Tony about them. Uncle Dick is Richard Curtis Van Loan, aka the Phantom Detective. Big Uncle Jim is Jim Anthony. Uncle Tony is Tony Quinn, aka the Black Bat. Information about the Sons that came from the Ashton-Kirk estate was recently stolen from the locked archives of a local university. Ashton-Kirk was a detective created by John McIntyre for The Popular Magazine; the stories were collected in four books. He, the Phantom Detective, Jim Anthony, and the Black Bat all appeared in "The Sons of Thor."