Treason's Harbour

Blurb

Treason's Harbour is the ninth historical novel in the Aubrey-Maturin series by British author Patrick O'Brian, first published in 1983. The story is set during the Napoleonic Wars.
Maturin finds Malta teeming with French spies. One is an unwilling spy, wife of a sailor taken prisoner, who needs Maturin's protection. The new fleet Admiral arrives, sending Aubrey on three missions in the Mediterranean, working with the Turks.