She learns that since leaving the Shop Where the Lost Things Go, she can easily find anything that's missing, which catches the attention of Seraphina, a spellbindingly-beautiful classmate who wants to exploit her powers to return home.

In hopes of escaping, Antsy and friends rush through a door leading to the world of goblins and fairies, from which Kade had been expelled.

The schoolmates get through another door, where they find Stephanie, a classmate from Whitethorn Academy, who has made a family among dinosaurs.

According to Booklist's Regina Schroeder, Mislaid in Parts Half-Known is a "satisfying installment for the Wayward Children series fans".

[1] Kristi Chadwick, writing for Library Journal, found that the "delightful portal fantasy will stick in readers' hearts".