John “Buck” McAllister was a decorated Pan-Pacific War veteran, former chief engineer of Energy Complex One, and the retired vigilante known as Captain Atomic Ace. Widely regarded as the guardian of New Radion Bay during its most volatile decades, McAllister became a symbol of Atomic Age heroism following the 1932 Radion Reactor Incident, which permanently altered his physiology. By the events of Year Zero, McAllister is a retired public figure attempting to live quietly as a father, having stepped away from vigilantism in 1944. His legacy, however, remains deeply embedded in the city’s cultural identity — and in the conflicts that resurface decades later.

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John McAllister was born in 1890 and moved to Radion Bay at a young age, the son of a steelworker and a church singer. From an early age, he demonstrated mechanical aptitude and a compulsion to repair what others abandoned. He served in the Pan-Pacific Conflict as part of the motorized cavalry, earning distinction for his battlefield rescues and rapid-response operations. During the war, he met Eleanor, an Army nurse who would later become his wife.

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Following the war, McAllister enrolled at the Radion Institute of Applied Mechanics, eventually partnering with Japanese refugee Yoriko Takeda in the early development of the tech company Takeda Dynamics. By the early 1930s, he served as chief engineer of Energy Complex One, one of the city’s most ambitious atomic infrastructure projects.

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In 1932, a catastrophic reactor malfunction forced McAllister to manually intervene in order to prevent mass casualties. The radiation exposure left him near death. Takeda Dynamics undertook an experimental reconstruction procedure to save him. McAllister’s organs, skeletal structure, and cardiovascular system were augmented and reinforced using advanced, proprietary technology. The transformation granted him extraordinary strength, durability, and resilience.

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He became Captain Atomic Ace soon after.

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In 1944, following years of public heroism and the death of his wife Eleanor, McAllister formally retired from vigilantism to raise his daughter, Kayla.

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