May is in the wilderness when it happens, which is probably good. Her spells should never go wrong - lack oomph, perhaps, but not go wrong - but the artifact she's studying, what she'd been sold as a blank medallion, is apparently no such thing, and she made the mistake of not being in contact with it at the moment of the spell going off.
It interacts somehow and she's somewhere else.
She has her backpack and her clothes and her own medallion tucked under her shirt and that's it. She blinks against the adjusted light conditions, takes stock of where she's landed.