Simon felt his phone buzz in his pocket, but ignored it. He was trying his hardest to keep a conversation going with the twins, even though every attempt he made to take it beyond political philosophy had so far hit a brick wall. So he took a swig from his water bottle, and tried -- not without a sneaking sense of futility -- to once again get some non-academic chat going.

"So which dorm are you guys living in?" he asked.

"Oh, we don't," said Sasha absent-mindedly. "We live in an apartment on the south side of town, near the beach. Mummy and Daddy set it up for us."

Simon...