O’Brian announced long ago that he hoped to write 20 volumes in his series centering on the British Navy during the Napoleonic Wars and featuring Jack Aubrey and Stephen Maturin. Along the way, he has built up a huge British following, if a lesser one in the States, although American reviewers find the series splendidly literate. And so here is volume 20, which finds Napoleon defeated at Waterloo and Jack and now-widower Stephen at Gibralter, sent on a mission to release Spain’s naval stranglehold on Chile and help Chile gain her independence. Nearly half the duo’s crew, however, a ragtag bunch of the stupid and least-skilled, has deserted. And an accident in the roaring darkness as the Surprise sets forth requires that it be put up for repairs. During this period Stephen falls in love with Christine Wood, a naturalist, and asks for her hand in marriage. The journey around Cape Horn to Chile takes the Surprise through the most southerly and icy of horrors. Meanwhile, Jack has the nurturing of Midshipman Horatio Hanson, the engaging bastard son of a future king of England, to think about. The climax comes when the vastly outmanned and outnumbered Surprise attacks the Spanish fleet. Escape at its most intelligent and demanding. Is this the farewell Aubrey/Maturin novel? Not very likely, with the gingery addition of Horatio Hanson to the mix.