#PennedPossibilities 879. How would your antagonist locate someone in a crowd?

(Laundry Files): He'd have a minion order the Chief Constable of whichever metropolitan police force is closest to the scene to send a riot squad to kettle the crowd and process them until the Person of Interest was found. In extremis he'd send the Home Office duty 'superhero' squad. Or maybe the army.

When you're PMUK *and* avatar of an Elder God basically all options are on the table, short of a Trident strike.