"So it's a camera, a telephone and a telegraph," he points out - they do have messages by text, thank you very much. "All rolled into one neat little package. Suppose I should keep an eye on it so people don't go breaking down my door trying to bother me."

The grin widens with a flick of one eyebrow. "Can't say I'm much of a time traveller, mind you. Only went forwards that whole time I was alive, and I don't reckon this place is followin' our good old Roman calendar. You might need to try harder than that, pal."