The Shadow Spies (Elsewhere Chronicles)

With the Shadow Door shattered and the passageway closed, Rebecca and Max set out across the dangerous lands of ElseWhere to find a way home. Wherever there is darkness, the Shadow Spies - servants of the Master of Shadows - lie in wait to stop them. Back on the other side of the door, Noah and Theo are working on a rescue. With the clues left behind by Grandpa Gabe and the help of new allies, can they find another passageway and keep the Shadows from destroying our world?