And they don't just happen for the sake of happening, these misfortunes. Pretty much everything that befalls our splendid duo is in some way a consequence of a prior adventure of theirs, or of suppositions relating to those adventures, to wit the "horrible old Leopard" which they barely survived commanding in Desolation Island and limp into New Holland after having been given up for dead at the beginning of The Fortune of War. The Leopard was an actual and infamous ship due to an incident in 1807 when its crew attacked the USS Chesapeake as part of an effort to capture some deserters from the Royal Navy, causing a diplomatic row and earning the Leopard a bad reputation among Americans*, with which reputation Jack Aubrey is tarnished when a series of calamities land him as a sort of convalescent/prisoner in Boston.
All that, though, is merely prologue to the land-based adventures of Maturin in Boston! For at its heart, The Fortune of War is a spy novel, and Maturin has been a very effective secret agent, even to planting a heap of poisonous misinformation on American spy
And of course, this is also the novel in which Maturin sort of half-assedly gets his heart's desire -- meaning the dashing, courageous, graceful and good-looking Diana Villiers, who has broken said heart several times but is now as trapped in America as are Maturin and Aubrey and Needs Stephen's Help. Just as Stephen has sort of decided maybe he's not in love with her anymore. Ah, me.
On to the next Napoleonic War adventure!
*And is also considered by some to be one of the causes of the War of 1812.