Dan Carlin's Hardcore History: Addendum is the companion feed to Carlin's main history series, home to his author conversations, solo pieces and some genuine oddities. He is candid about the limits: reading for the main show leaves little room for other books, so he describes himself as constrained in how many author interviews he can take on. When one happens, the preparation shows. With Alex Wellerstein, he quotes the book back to its author and sits with its argument that Truman may have misunderstood the targeting of Hiroshima, trying to picture the moment the reports made the truth plain. The talk lingers on the firebombing of Japanese cities, which, as the conversation notes, no reporter ever raised with Roosevelt or Truman. It then runs forward to Kennedy realizing during the Cuban Missile Crisis that he did not control every pathway to nuclear war. Carlin acknowledges that nuclear weapons are well-trodden ground here and says he makes no apologies for it. The episode list agrees, with Annie Jacobsen on how a nuclear war might unfold in 'The Handmaidens of the Apocalypse', Fred Kaplan in 'Strangelove Whisperings' and Malcolm Gladwell on Curtis LeMay and precision bombing in 'Gladwell and the Bomber Mafia'. 'Sledgehammer and Big Shot' brings the Pacific war down to one family. Henry Sledge, son of the Marine memoirist Eugene Sledge, recalls his father breaking down during the tank battle in the film Patton and describes the elder Sledge's hostility toward Nimitz over Peleliu. He calls 'With the Old Breed at Peleliu and Okinawa' a book that makes Marines fiercely proud yet is, at its core, a powerful anti-war statement. The map reaches well beyond the twentieth century. Zeinab Badawi arrives with a book spanning the whole of African history, and Carlin, by his own admission, monopolizes her on the ancient kingdom of Kush. She argues for oral tradition and Arab chronicles as sources Western historians tend to overlook, and explains why she resists calling the Kushites Nubians. Steppe nomads with Kenneth W. Harl, the Middle Ages with Dan Jones and Actium with Barry Strauss fill out the older eras. Then come the swerves. Rick Rubin on creativity, Mike Silver on whether modern boxers could compete with fighters of earlier eras, Carlin's own background in miniature wargaming, a retrospective on Bill Barrett as the voice of his podcasts, even an episode where Jeff Marek turns the tables and interviews Carlin. The solo work has its own flavor. 'So, you say you want a revolution?' repurposes older material on the late 1960s, from a wave of bombings and bomb threats to the Prague Spring and Robert F. Kennedy's run, and sets 1968 beside the present, offering social media as a rough counterpart to the role drugs played then. What comes through across all of it is an interviewer who is plainly a fan, apologizes for hijacking a guest on a pet subject, and then does it anyway.