Jake recognised the route from Hoxton down towards the Embankment and then along to Vauxhall Bridge, where they turned left. He assumed they were heading for the SI6 building on the south side of the Thames and, sure enough, they took another left and then down a slope into an underground area.
Jake noticed that the route had been continuously moving which implied he had received some priority treatment based on being part of a cavalcade of police cars. He thought this was a new record to cross this area of London.