That particular day had been the last day of planning for any pre-battle strategies, and as it drew to a close, Hermione was feeling weary. As a result, her magic was spontaneously casting charms on things, and she had found herself at one point covered in pillows the moment she thought of how nice it would be to go home to bed. Snape had laughed at her misfortune, surprising everyone in the room at his uncharacteristic outburst of mirth.