Desmond heard Nurse Ann talking about chores. He looked again at the floor, which now never looked like it'd been tampered with. He didn't want to leave them here alone, but he had to show up for his chores if he had any or they'd get suspicious... He made one last check that he knew where they were and he walked out of his room. 

He looked at Nurse Ann and smiles. "Nurse Ann, you look lovely this evening." One final compliment before I destroy this hell, and put you wretches out of business, he thought. She's probably going to not even be suspicious and chalk it up to trying to get out of his chores or something. Sometimes adults were so easy to trick like that...