It would have been very difficult for the conspirators to keep the plot secret, as so many were involved, so it is not surprising news of it leaked out. In a kind of parenthesis to the day’s business, the Clerk of the House, Ralph Ewens (or an assistant), made a marginal note of the most spectacular event to have occurred in the House to that date.
The famous marginal note begins (in modern English):
"This last night, the Upper House of Parliament was searched by Sir Thomas Knyvett, and one Johnson *, servant to Mr Thomas Percy, was there apprehended, who had placed 36 barrels of gunpowder in the vault under the House with a purpose to blow [up] it and the whole company when they should here assemble"
* “Johnson” was the alias Fawkes used prior to his confession.
Fawkes is said to have been taken before Cecil (Secretary of State) and King James himself in the early hours of 5th November. He maintained a scornful attitude, and refused to answer questions about his co-conspirators. However, their identities were probably no secret, and all (except Robert Winter) were killed or arrested by 12th November. On 5th November there was apparently great rejoicing in London; and the following Sunday 10 November was also ppointed a day of thanksgiving.
Several conspirators, including the ringleader, Catesby, had fled to the Midlands and been shot there. Those who remained alive were taken to the Tower of London from 6th November onwards. All of them were then probably subjected to extensive and cruel torture - much used at this time, though never officially sanctioned by English law.