The walk moves around the corner, to this elegant building, once a house of detention and where, in 1867, the leader of the Irish Republicans, Richard Burke, was being held. Reading something like a Keystone Cops scene, his compatriots plot to free him by blowing a hole in the wall at the time the prisoners were normally exercised. The first time they try this, the bomb fails to explode. By the next day, the plot had become known to the intelligence service and the prisoners moved. The plotters, knowing nothing about this, try again. This time the bomb blows up catastrophically - blowing an 80 foot hole in the wall, but also knocking down houses and killing twelve including children, injuring many more. It became known as the Clerkenwell Outrage, and had a very negative effect for the Republican cause.