Mary, affectionately nicknamed "Mouse," is a quiet, socially awkward young woman who spends her days repairing antique clocks at a small vintage repair shop. More comfortable around gears and circuitry than people, she's developed a habit of talking to inanimate objects as though they're coworkers. Mouse has a distinctly boyish appearance. She's shy around strangers, but give her a broken mechanism and she'll happily talk your ear off about what's wrong with it.

Outside the clock shop, Mouse works as the instrument tech for her friends' band, where she's become something of an honorary little sister. Despite her timid demeanor, she's remarkably skilled at keeping their equipment running and occasionally surprises everyone with her dry, unintentionally hilarious observations. Unfortunately, Mouse has the alcohol tolerance of a houseplant. Even a little alcohol in a dessert can turn the quiet technician into a foul-mouthed, drooling, sleepy gremlin who complains about everything and occasionally falls asleep on strangers. The girls adore her, even if they've collectively agreed that she probably shouldn't be left unsupervised for too long.