The phony war that wasn't -- Caught hopping -- Rash moves -- The end of the beginning -- U-boats on the rampage -- Churchill declares "the Battle of the Atlantic" -- Moving the goalposts again -- America goes for it -- Secret weapons -- Fingers in the dyke -- Shifting fortunes -- Beating the drum -- Overstretched everywhere -- Disaster in the Arctic -- Goading the bear -- Dönitz seizes his chance -- Changes at the top -- "The Battle of the Air" -- A very narrow escape -- A dramatic turnabout -- The reckoning -- The beginning of the end -- Epilogue: fates disentwined.