Jason Burke investigates the network of Islamic radicals who found a haven in England and turned its capital city into Londonistan, the world HQ for jihad atrocities Mohammed was surfing the internet when he heard the shouting. He ran down the stairs from his cheap flat overlooking north London's Seven Sisters Road and out into the street. It was bitterly cold. Two friends were outside. 'The police are in the mosque,' they told him. From overhead a helicopter sent a powerful beam of light against Finsbury Park mosque - a modern brick building with dark windows and a minaret above....