Let's rewind the clock to T-minus 20 seconds to the beginning of Tristram. Book 1 begins with Tristram's conception, which went wrong because Mrs. Shandy interrupted Mr. Shandy exactly at the moment of ejaculation. He then introduces Yorick and Toby—not to mention Toby's is-it-or-isn't-it wound—and lays out a few things we need to know about hobby-horses and digressions. These two subjects show up a lot. Like, a lot. Check out Book 1, as Tristram digresses about writing, philosophy, marriage, and even digressions; and we learn about Mr. Shandy's obsession with names (as well as Tristram's obsession with obsessions).
In Book 2, Tristram finally gets to his birth. As he's being born (seriously), he explains how Toby became obsessed with building fortifications; then, he digresses for a while about the philosopher John Locke while Susannah goes for the midwife and Obadiah goes for the doctor (and then leaves again for the doctor's tools). All at the same time, Toby and Mr. Shandy each have a one-sided conversation: Toby explains his fortifications, and Mr. Shandy keeps ranting about obstetrics.
In Book 3, Tristram is… still being born. Hang up your hats, because this is going to take a while. Book 3 is the catastrophic volume. Not only is Mrs. Shandy screaming upstairs while she labors, but Mr. Shandy contorts himself trying to extract his handkerchief from his pocket; Dr. Slop cuts his thumb trying to untie the knots of his doctor's bag; Susannah scrapes her arm; the midwife bangs her hip in a fall; Dr. Slop scrapes Toby's hand demonstrating the forceps; and—oops—Dr. Slop breaks baby Tristram's nose in the delivery. It's a good thing this is pre-malpractice suits.
Book 4 kicks off with a long-anticipated story from Slawkenbergius, a suggestive tale about a stranger who has such a large nose (no, really: a nose) that he sends a whole town into a heated frenzy. After the story, Tristram worries that, since he's already at Book 4 and still hasn't finished narrating the first day of his life, he's never going to finish the project. And then Susannah announces that the baby Tristram is dying and needs to be baptized. Mr. Shandy tells her to tell the parson to name the boy "Trismegistus," but Susannah forgets the name on the way and Yorick decides she must mean "Tristram." Mr. Shandy consults scholars to find out if he can be renamed, but they never resolve the issue. And then things pick up speed: Mr. Shandy receives an inheritance from his sister, and Bobby, Tristram's older brother, dies.
Hooray! In Book 5, Tristram is (1) born and (2) the new Shandy heir. Determined to make Tristram a smarty-pants, Mr. Shandy begins writing the Tristram-paedia, a textbook expressly designed for baby Tristram. Unfortunately, Tristram's career as future head of the Shandy family is almost cut short (pun intended) when he has an accidental circumcision. Surprisingly, Mr. Shandy takes the accident philosophically—noses, after all, are more important than penises.
Book 6 begins with the fallout from Tristram's circumcision. He's crying in pain while everyone argues about what to do, and the whole neighborhood thinks that his entire penis has been lopped off. Mr. Shandy decides Tristram has been spending too much time with women and resolves to make a man out of him. Toby tells a long, sad, and possibly pointless story about a man named Le Fever. Then, just when things have taken a turn to the Tristram, our narrator announces that he's going to turn his attention to Toby and Toby's love affair.
But not yet. In Book 7, Tristram heads off on a major digression—oops, we mean, journey—to Europe. Begin the sort-of-travel-narrative. He doesn't say much about what he sees, but he tells us a lot about how he feels and the little incidents that stick with him, like almost losing his notebook and having an affair with a pretty peasant girl.
In Book 8, Tristram takes us back more than a decade before he was born, when Toby first came to Shandy Hall. He stayed for a few days with the Widow Wadman, who promptly fell in love with him. He, meanwhile, ignored her for eleven years. Finally she carried out a subtle ploy: she asked him to look in her eye for a piece of dirt, and he fell for her. Not that Tristram tells the story in anything like that order—he starts with a digression, interrupts for Trim's story about the King of Bohemia, and then again for Trim's naughty story about being seduced by a nun.
Finally, in Book 9, Toby works up the nerve to court the widow (although not before Tristram spends a few chapters worrying about his writing style). Mrs. Wadman's servant, Bridget, tries to figure out from Obadiah what Toby's injury is like, while Mrs. Wadman tries to discover the same information from Toby. When Toby realizes that she's just after his penis, he's heartbroken. After dinner, he wants to talk to Mr. Shandy about it, but the whole company is interrupted by Obadiah's complaint about Mr. Shandy's impotent bull.
Yeah, that's it. That's the whole story.