The sky began to lighten, but the thestral ignored it as long as possible. As long as it was still night, it would be free. Free to race around the lake and across the meadows around the pitch. Free to frolic with the rest of the herd, or with the denizens of the forest. Free to graze on the lawn beneath the full moon and nibble the delicate, sweet sacred datura flower that spilled from the greenhouses.
But the sun was persistent, and soon the morning birds began to chirp. The thestral ignored them for as long as possible, but the sun continued to rise. The sky grew lighter, and finally the moon was a pale blot against the streaming golden light in the east.
Shaking her mane one last time, the thestral allowed herself to shrink and change and become once more trapped in the body of a small human child.
Soon the children would be heading down to breakfast, and whoever had locked the Ravenclaw commons last night would have to release their spell so that the others could get out. Moreover, while everyone was in the Great Hall eating, the common room would be empty. This was her chance to get in unnoticed and take a shower. She could get a clean uniform, if she had one left, and maybe see if she could find a second shoe. She had spent the night grazing, so it wouldn't hurt her to skip breakfast.
The girl walked towards the castle, prepared to face her Housemates and classes for another day, but inside her mind, she heard nothing but hoof beats, and felt the caress of a nighttime breeze through her mane.