The plot became known through a mysterious anonymous
letter to Lord Monteagle, a Catholic, warning him not to
attend the State Opening. Monteagle reacted by
organising a search on 4th November. At midnight, Sir
Thomas Knyvett, Justice for Westminster, found the
gunpowder and arrested a man named Johnson, who
claimed to be Thomas Percy's servant. Johnson was in
fact Guy Fawkes.
Fawkes was taken before Cecil, the Secretary of State, the following morning. Although he refused to answer questions, the conspiratorsΓÇÖ identities were already leaking out - and all except one were arrested or killed by 12th November.