[It's probably a good thing that this exchange is via voice and the Doctor can't see him rolling his eyes as, of course the Time Lord is more interested in the puzzle than his own impending agonising death.

This is why he put one of the nails of St. Padua in the Doctor's coat, trusting that he carries so much in there he won't really notice. Never knew when he'd have to track the blasted man down.

Constantine digs out his own nail and balances it in the palm of his hand for a moment before starting off in the direction it indicates.]

Yeah, well. Magic is starting to get stronger these days. If they've had any contact with someone like you before, could be that they've found a way to boost it to reach where it needs to.

How long have you been there? [It'd give him an idea of what kind of time frame he might have before things got a lot more serious.]