How was the Gunpowder Plot stopped?

The plotters got 36 barrels of gunpowder and hid them in the cellar under the Houses of Parliament. Guy Fawkes was put in charge of guarding the gunpowder.

A letter was sent to the King however, warning him of the planned attack and on the morning of the 5th November, soldiers found Guy Fawkes in the cellars waiting to light the gunpowder.

The soldiers arrested Guy, and took him to the Tower of London, where they kept him prisoner. They also arrested the other plotters and took them to the Tower too.