I got these two books for my birthday last year but found them hard to hold with a broken wrist. They stared at me from the not-read bookshelf, enticingly. And eventually I got them down, reading both in the space of three or four day. Long books, but great reads, especially if you like time travel contradictions, or just like London.

Historians in 2060 Oxford, England, are researching thepast. It’s a kind of hands-on research whereby they travel into the past, withs...