Mai is swimming. It's a hot summer weekend, so the beach is crowded and noisy; but here underneath the surface, welcomed by the water, the world is quiet and cool and just for her.
She turns a few somersaults and comes up for air. She wipes the water from her eyes and floats there, for a moment, letting the dizziness from the somersaults subside.
...It's taking longer than it should. She spins herself the opposite way from the world around her, to undo it, but that only makes it worse. The horizon tilts sideways, and without her meaning to, her head slips under the surface.