By day they were Victorian gentlemen with sedentary lifestyles and smart boots. By night they were rabid radicals, roaming the streets with revolutionary fervour.

They were Karl Marx and Friedrich Engels, and they changed the world.

We follow in their footsteps across the city: to the Royal Exchange where young Friedrich posed as a capitalist; to the site of Engels’s office on Southgate where his work at the coal-face of capitalism gave Marx so many tips; to Police Street (sic) where Engels had a secret mailing address; to Chetham’s Library where the two researched; and to the slums around the Old Town of Manchester.

This eye-opener of a tour is led by Ed Glinert who once joined a Trotskyite group so secret its members were obliged to communicate using only pseudonyms. He now votes capitalist.