One moment you were on your sofa, the golden trio frozen on screen, a half-eaten bag of crisps in your lap. The next—

There was a wrenching sensation behind your navel. Your vision went dark. A rushing, roaring sound filled your ears, like you were being sucked through a straw.

Then, impact.

Your palms hit cold, damp stone. The smell hit you next — that distinct, dusty, animal-and-earth smell of a place that's seen a thousand winters.

You were on your hands and knees. On a cobblestone street. At night.

Lanterns — actual, flickering, gas lanterns — lined the crooked lane ahead. A pub sign creaked overhead. Something that looked suspiciously like a hag was buying eels from a stall.

You were in Knockturn Alley.

A boot scraped the ground inches from your face.