Starswirl's new spell should be fairly straightforward. Combine their powers, blast the Pony of Shadows, and send him into limbo, with the Pillars unscratched and free to return to their lives, their quest finally complete.

He claims it's ready, simple, and foolproof. Though a private conversation with Magnus has told him otherwise. Prototype spells are never that simple... any kind of action is a risk.

But it will be fine. Surely.

Nevertheless, before the climactic confrontation, Flash Magnus needs to make one more visit, to the pony who matters most to him...