Root observes that the U-boat is like a tunnel bored out of the sea and lined with hardware. This cabin (if that’s not too grand a word for it) is by far the largest open space Root has seen, meaning that he can almost stretch his arms out without hitting someone or inadvertently tripping a switch or a valve. It even sports some wooden cabinetry, and has been sealed off from the corridor by a leather curtain. When they first brought Root in here, he thought it was a storage closet. But as he looks around the place, he begins to realize that it’s the nicest place on the whole boat: the captain’s private cabin. This is confirmed when Beck unlocks a desk drawer and produces a bottle of Armagnac.