Board Thread:Show-Related Questions and Answers/@comment-24243167-20131224102233/@comment-1423293-20151213000544

Just to throw my two cents in here: when Gold's shadow returned, it seemed like Pan was almost attached to him, he couldn't break free despite apparently having magic to do so. So my theory is that Gold attached the shadow to both of them and used the dagger to kill himself, thus also dragging Pan down to the Underworld with him.