A 10-year-old self-proclaimed cynic finds herself rescuing and befriending a squirrel after it is sucked up by a vacuum cleaner. This squirrel, having experienced such a trauma, develops superpowers: it has super strength, can fly, and can type. The girl, Flora, names the squirrel Ulysses (after the vacuum cleaner), and together they go on adventures, such as surviving vicious diner staff, challenging Ulysses's arch-nemesis (Flora's mother), and battling the evil Mr. Claws (Flora's father's landlord's cat). Throughout this wacky yet endearing tale, Flora and her new friend William Spiver struggle with and partially overcome feelings of abandonment, loneliness, and longing to be loved.