Jem had spent much of the last week in bed, ill, and was well aware that he caused his Parabatai a great deal of anxiety. Now that he felt stronger, he wanted to show Will that he had little need for concern, in a way that would appeal to Will - with a prank.

The lid of Yin Fen was drawn back and Jem slid a hand in to withdraw the smallest pinch of the drug.

A bell tolled twelve strokes and he smiled to himself. It was not unusual for him to be awake at such an hour, but it was unusual for him to be adventuring forth from the Institute, without Will by his side. He padded out, and cut a path through the quiet streets to the park.

Ten minutes later, he returned with a bulge under the coat and made a beeline for Will's room. He stood at the door for a minute to make sure that Will's breathing was even and that he was safely asleep. Assured that he had a window of opportunity, he opened the door, and let the disgruntled package lose.

He closed the door and waited outside as the first loud 'quack' echoed through the room.