The catastrophes that befall Tristram are actually relatively trivial; only in the context of Walter Shandy's eccentric, pseudo-scientific theories do they become calamities.

The second major plot consists of the fortunes of Tristram's Uncle Toby. Most of the details of this story are concentrated in the final third of the novel, although they are alluded to and developed in piecemeal fashion
from the very beginning. Toby receives a wound to the groin while in the army, and it takes him four years to recover. When he is able to move around again, he retires to the country with the idea of constructing a scaled
replica of the scene of the battle in which he was injured. He becomes obsessed with re-enacting those battles, as well as with the whole history and theory of fortification and defense. The Peace of Utrecht slows him
down in these "hobby-horsical" activities, however, and it is during this lull that he falls under the spell of Widow Wadman. The novel ends with the long-promised account of their unfortunate affair.

Overall Analysis and /Themes

The most striking formal and technical characteristics of Tristram
Shandy are its unconventional time scheme and its self-declared
digressive-progressive style. Sterne, through his fictional author-character
Tristram, defiantly refuses to present events in their proper chronological
order. Again and again in the course of the novel Tristram defends his
authorial right to move backward and forward in time as he chooses. He
also relies so heavily on digressions that plot elements recede into the
background; the novel is full of long essayistic passages remarking on what
has transpired or, often, on something else altogether. Tristram claims that
his narrative is both digressive and progressive, calling our attention to the
way in which his authorial project is being advanced at the very moments
when he seems to have wandered farthest afield.

By fracturing the sequence of the stories he tells and interjecting
them with chains of associated ideas, memories, and anecdotes, Tristram
allows thematic significance to emerge out of surprising juxtapositions
between seemingly unrelated events. The association of ideas is a major
theme of the work, however, and not just a structural principle. Part of the
novel's self-critique stems from the way the author often mocks the
perverseness by which individuals associate and interpret events based on
their own private mental preoccupations.