Miri expects people to be nicer than they turn out to be; other people expect Miri, the inconvenient woman, to conveniently disappear. On the rare occasions when someone doesn’t already know who she is, Miri improvises unconvincing reasons for her spotty resume or outdated frame of reference: She’s been traveling in Burma, she’s been on a really long diet.

What complicates the situation, and gives “Back to Life” an extra comic kick, is that the duplicity and discomfort come from every direction. Miri, who’s clearly a kind and gentle soul, if sarcastically minded, at first takes the suspicion and resistance she encounters — which ranges from rude remarks to vile graffiti and a brick through a window — as her due. But eventually she cottons to what we already know, or can pretty easily guess: The people she’s closest to, including her mother, Caroline (Geraldine James ), her former best friend, Mandy (Christine Bottomley ), and the affable new neighbor, Billy (Adeel Akhtar ), are harboring secrets that start to make her own past transgression look tolerable.

“Back to Life” may be premised as a spin on a couple of standard narratives, the “woman starting over in a world with no place for her” and the (usually male) “life-after-prison” stories. But most of its comedy stems from the effect Miri has on everyone around her, and its primary pleasure comes from its gallery of supporting performances: James as Miri’s waspish, selfish, covertly sexting mom and Richard Durden as her gruff, eco-warrior dad; Bottomley, echoing the prickly defensiveness of her role in “The End of the ____ing World”; and the wonderfully warm Akhtar. Haggard, with her distinctive features — a cross of Modigliani portrait and midcareer Penny Marshall — plays Miri as a bashful but stubborn catalyst for the action, an unavoidable object disrupting 18 years of small-town rationalization and avoidance.

When it focuses on being a tart, melancholy, frequently dirty treatise on indignity, reconciliation and clashing expectations, “Back to Life” works quite well. ( A typical exchange in which two characters review each other’s liabilities: “You killed someone!” “You’re married!” ) What doesn’t work so well is the mystery plot, increasingly obtrusive as the season progresses, in which a cryptic freelance “investigator” digs into the circumstances of Miri’s teenage crime. (It involves a dramatic setting that clearly, but irrelevantly, invokes the murder drama “Broadchurch.”) Details of that catastrophic incident are dribbled out to the viewer in a way that’s slightly irritating even as it is crucial to the show’s structure.

The question of what Miri did, and why, is so prominent throughout the season that other threads aren’t (or don’t need to be) fully developed; when it’s answered, you’re not exactly sure whether there’s more for the show to do.