“Hmf. There's a lot of forbidden spells in the archives. Not where anypony can get to them, of course,” she hastily added. “I suppose it might be a variant of one of those. The ancient unicorns came up with some pretty . . . interesting spells.” Twilight tapped her chin with her hoof. “They've got almost no natural magic weave.” She looked longingly at the girl. “It's touch and go whether Zecora's salve is going to be able to save her hand. There’s virtually no framework to build on. If it works at all, it’s going to take a long time.”