Seanan McGuire's Across the Green Grass Fields (Tor.com, 2021), a stand-alone novel in the Wayward Children series, a portal transports a horse-loving ten-year old, Regan, to Hooflands. Soon she becomes part of a centaur herd, learning how to herd unicorns, finding her place as an apprentice healer, and making a new best friend her own age, a centaur girl named Chicory. She finds herself at ease in her new role and other than missing her parents, would be content to continue in her life. But the population of Hooflands has expectations for her, expectations that even running away can’t evade. Humans have always saved Hooflands from bad things. And too soon, it will be Regan’s turn.