The Dim - Marie D. Jones - Bog

Monsters are real...and they live in The Dim.
Bobby Vega's little sister Sally is missing. She is #12.
When a mute handyman, Joe White Eagle, is accused of the disappearances of several local children, Bobby knows something is amiss. Even Detective John Redbird can feel it in his bones that Joe is innocent. Joe reveals the truth about where the children are, trapped in a shadowy realm called The Dim, an alternate world Joe barely escaped as a child. A world only children can enter. A world where monsters are real, and children are their victims.
To find his sister, Bobby must enter The Dim and navigate a deadly maze of doors and rooms that all lead to the Wiggle Man-the interdimensional ruler of The Dim, who feeds on the souls of innocents. During his narrow escape, Bobby frees some children but learns hundreds more remain trapped, and their time is running out.
Now, with the help of Joe and Detective Redbird, Bobby must return to The Dim with a handful of child warriors and some unusual allies to battle the Wiggle Man. Can they rescue the remaining children and close the door between worlds, or will they be lost forever?