Following a misjudgement by its ambitious young captain, a German WWI U-boat is forced to wait for a prolonged period on the bottom of the North Sea, facing the threat of enemy torpedo ships. This causes unprecedented physical and mental challenges for captain and crew.

Finding himself in a new era, and approaching retirement, Indy wrestles with fitting into a world that seems to have outgrown him. But as the tentacles of an all-too-familiar evil return in the form of an old rival, Indy must don his hat and pick up his whip once more to make sure an ancient and powerful artifact doesn't fall into the wrong hands.