Seamwalkers, Prompt 7

>> ring bell

You take the tarnished bell out of your pocket and ring it. A whooshing sound begins whooshing in the air above you. All the butterflies in the meadow, save one, make their way toward you. A sylph appears out of the whooshingness, floating in the air. She smiles at you. She motions to the butterflies, who gather and form a wiggling, imperfect rectangle that is roughly door-shaped. Through the doorway you can see...the rest of the meadow. The sylph frowns, "We seem to be short a butterfly. I'll have to get back to you." The sylph disappears, and the butterflies scatter. You put the tarnished bell back in your pocket.

>> ?