THEY were on Chambers Street when it happened.

It was a Saturday afternoon and they had come back to the gallery district because Ifeanyi had been told by a colleague about a bookshop two doors down from the gallery that specialized in architectural texts, and he wanted to find a specific out-of-print title. Then, Amelia had said she would come because she needed a Saturday that did not involve spreadsheets and the bookshop was supposedly excellent.

It was excellent. She spent forty minutes in it and left with three books she hadn't planned to buy, which she considered a mark of quality.

They were walking back toward the car park...