Whirlwind continues the series Clavell began with Tai-Pan (1966), which told of the origins of Noble House in 1841. This trading company based in Hong Kong has now become a multinational conglomerate, which secretly owns Maclver's Iranian helicopters. Its future hinges on their recovery as the worthy Andrew Gavillan and the shifty usurper Linbar Struan struggle to control its destiny. Armstrong, the British superagent last seen in Hong Kong in the novel Noble House (1981), is in Whirlwind, still trying to save the last vestiges of the British Empire from the Chinese, the Russians, and from itself.

Clavell himself calls his novels parts of an "Asian Saga," which also includes King Rat (1962) and Shogun (1975).