Co-organised by the National Archives and the Metropolitan Police, it asks visitors to re-examine the evidence and "forget, forget everything you think you know" - for example, Guy Fawkes was not arrested in the cellar surrounded by gunpowder barrels.
Police files on the wall identify 24 key players, including fall guy Fawkes and Robert Cecil. Did Cecil, the Spymaster General, use the plot for his own ends, and was intelligence concealed until the last minute? Was Shakespeare's London justifiably paranoid about invasion from the European Catholic superpowers? On display are the suspects' confessions and original Crown prosecution evidence, including the controversial letter to Lord Monteagle, warning him to stay away from Parliament on November 5.