Just as they each were about to touch the mirror, Ally heard her grandmother. "Ally? Is your grandpa up there?" Unfortunately, the sudden sound of her grandmother's voice threw off Ally's concentration. But only for a moment.
Ally immediately re-focused on pushing her grandfather's hand towards the mirror, and after a blue flash of light, her grandfather turned to her and said "Ally, I'm back." He smiled and then Ally smiled too. All was well.