Mescal had always had its routes into the world, as this novel's complex relationships show: Starling knows a chemist named Roper, who knows a painter named Jourbert, who knows a man in Mexico who works for the government. There has been a new shipment of mescal, but it is not quite what anyone expected. This is a new drug that opens the doors of perception for a man such as Roper, hiding away in his north London laboratory. He can make people work for him and turn his friends into fools or murderers--if only he could control his own mind.