Maze spell and Demi-Planes

[Marcron]

While fighting an evil sorcerer in a a Demi-Plane she created the fighter of our party was victim of a Maze spell. On the next turn he failed his Intelligence check to escape then the Paladin of the party smote the evil b***h ending her reign of terror. Her death caused the Demi-Plane to collapse and ejected the rest of the party back to the Prime Material Plane. This left the whole group with one big question, what happens to the Fighter stuck in the Maze? After ten minutes he will return to the point he was at when the spell was cast, or be moved to the next unoccupied space; but what if he has to return to a place that no longer exists? What would be the next space he can occupy? Would he be lost in the astral or ether plane? Would he cease to exist, just like the Demi-plane the sorcerer created?

[Claxon]

Seems like the common sense answer is he too is ejected onto the material plane just like all of you were.

AFAIK there are no rules that cover this.

[Lincoln Hills]

This is probably up to the GM, and varies a bit based on whether the usual cosmology is being used; but the usual default assumption is that objects that no longer have a 'home' are expelled into the Astral Plane. It's sort of the cosmic dumping ground.