Tristram writes a chapter on sleep — apropos of the fact that everyone is asleep — and he sticks to the subject.
Walter asks Susannah to send "Trismegistus" down so that he and Toby can see him. The request touches off a general panic: Susannah confesses that the child has been named "Tristram," and Mrs. Shandy is in a "hysterick fit" about it. Walter calmly puts on his hat and goes out.
Tristram explains why his father went out to the fish pond with this latest affliction instead of taking it upstairs to the bed as before: first, it was different, and second, there is something about fish ponds.
Trim enters and tells Uncle Toby that "it" wasn't his fault — meaning the cow's breaking down the fortifications (first mentioned in Book 3, Chapter 38) — and Toby reassures him that it was the fault of Susannah and the curate — meaning the misnaming of Tristram. They agree that names don't mean very much in the long run, in the heat of battle: Trim would have fought as gallantly under his own name (James Butler) as he did under his nickname. They are acting out a valiant offensive when Walter reenters. He seats himself and begins his lamentation: everything has so far gone wrong for his child, but the name "Trismegistus" might have fixed it all: conception, infelicitous gestation period (because Mrs. Shandy "fumed inwardly" about not being able to go to London to have the baby), pressure on the skull by being born head first, crushed nose. Toby recommends sending for Parson Yorick.
