And I found myself in a corner of Blackwell's Book Store. Its dark woods and book-lined walls are not only instantly recognizable but timeless, and for a moment I thought I'd made it back to 2057, and getting to the lab was going to be a simple matter of sprinting up the Broad to Balliol, but as soon as I poked my head round the bookcase, I knew it wasn't going to be that simple. Outside Blackwell's bow windows it was snowing. And there was a Daimler parked in front of the Sheldonian.