Ball's departure from the mystery genre was a bestselling what-if? political thriller The First Team, published in September 1971. In the 1960s and 1970s, the genre of political thrillers born of the Cold War included writers such as Allen Drury (who wrote Advise and Consent in 1959), Fletcher Knebel (Seven Days in May), and Edwin Corley (The Jesus Factor). They combined politics, paranoia, and traditional hero characterization to thrill mostly male readers and were the staples of airport bookstores.

The First Team starts after the USA has surrendered to the Soviet Union (never actually named within the novel) without firing a shot. The takeover is possible because of widespread cultural malaise. Undermined by Hippies and anti-war protestors, corrupt military-industrial complex producers providing faulty fighter planes, weak-willed politicians, and the Communist propaganda machine (not to mention the Vietnam War's hangover), the USA was unable and unwilling to defend itself.

The leader of the occupation forces is an iron-willed bureaucrat, backed up by a vicious secret police Colonel. White House interpreter Raleigh Hewitt, kept at his post due to the invaders' laughably poor command of English, is recruited into an underground resistance organization called "The First Team." It turns out that the fall of the United States was foreseen, and this ultra-secret agency schemes to free the country again. Pre-dating Tom Clancy's The Hunt for Red October, The First Team contains details about the US nuclear submarines, abduction of one of which saves the day.

The First Team appeared more or less simulataneously with Vandenberg by Oliver Lange, dealing with the same theme of a Soviet-occupied United States, but far more pessimistically - with resistance restricted to a small group of oddballs in a corner of New Mexico. Both are part of the genre of Invasion literature, like The Battle of Dorking in 19th century Britain.

Virgil Tibbs series

• In the Heat of the Night, Harper & Row Publishers, 1965
• Cool Cottontail, Harper & Row Publishers, 1966
• Johnny Get Your Gun, Little, Brown, 1969 [ISBN 0316079456]
• Republished as Death of a Playmate, Bantam 1972.
• Five Pieces of Jade, 1972
• Eyes of the Buddha, Little, Brown, 1976.
• Then Came Violence, Doubleday, 1980. [ISBN 0385157266]
• Singapore, Dodd, Mead, 1986, [ISBN 0396087639]
• short stories published in Ellery Queen's Mystery Magazine:
• "One for Virgil Tibbs" Feb 1976
• "Virgil Tibbs and the Cocktail Napkin" Apr 1977
• "Virgil Tibbs and the Fallen Body" Sep 1978

Others

• Operation Springboard, Duell, Sloan and Pearce, 1958.
• Rescue Mission, Harper & Row, 1966.
• Miss One Thousand Spring Blossoms, 1968.