In Return to Camlann, the third book in the fast-paced thriller series featuring Hardington Tachman (aka Hardtack), Hardtack is repeatedly mistaken for an identical twin brother he doesn't even know exists. Following horrifying events in Africa and India, Hardtack has returned alone to America while his wife, Mei Li, who has lost her memory, lives in Italy with Tino, her new lover. Hardtack begins a desultory relationship with Maria who becomes desperate when Mei Li suddenly returns. Hardtack and Mei Li grope to mend their strained relationship by taking a trip to Mexico, but it is there that members of a drug cartel spot Hardtack. They mistake him for his brother, a drug enforcement agent and when they see Maria embracing him, her bother, the cartel chief, refuses to believe she's not a spy - with fatal consequences.

Hardtack later travels to the American southwest for a conference and embarks on a relationship with Eva, as a consequence of his doubt about Mei Li's fidelity. The conference turns out to be a hoax, which leads to a final reckoning in the town of Camlann. In an explosive confrontation, true identities are uncovered and shocking secrets are unearthed.