The Stone Child by David A. Robertson

It's a race against time to save Eli, in this third book in the award-winning, Narnia-inspired Indigenous middle-grade fantasy series.
After discovering a near-lifeless Eli at the base of the Great Tree, Morgan knows she doesn't have much time to save him. And it will mean asking for help - from friends old and new. Racing against the clock, and with Arik and Emily at her side, Morgan sets off to follow the trail away from the Great Tree to find Eli's soul before it's too late. As they journey deep into the northern woods, a place they've been warned never to enter, they face new challenges and life-threatening attacks from strange and horrifying creatures. But a surprise ally comes to their aid, and Morgan finds the strength to focus on what's most important: saving her brother's life.