The Surgeon's Mate (Aubrey & Maturin, #7)

Jack Aubrey and Stephen Maturin are ordered home by dispatch vessel to bring the news of their latest victory to the government. But Maturin is a marked man for the havoc he has wrought in the French intelligence network in the New World, and the attention of two privateers soon becomes menacing. The chase that follows through the fogs and shallows of the Grand Banks is as tense, and as unexpected in its culmination, as anything Patrick O'Brian has written.