By the end of 1605, according to his confession, Rookwoode was approached by Catesby, Winter, and Wright, he stated that he hadn't known the reason for supplying the men with gunpowder at a house in Lambeth. This may be true, Catesby, as the ring leader, was a determined man and also charming and it may be that Rookwoode was easily persuaded.
After the capture of Fawkes, Rookwoode was among the men fighting the king's forces at Holbeche House in Staffordshire, he was shot in the right arm and his face burnt, he was captured and taken to London and 'questioned at great length.' During his trial, he stated that he was led astray by Catesby and pleaded not guilty. Labeled a traitor, he was destined for a traitor's death, four days after his trial he was drawn to his death. Rookwoode asked to be taken past his home where his dutiful wife Elizabeth was waiting at the window, he is said to have shouted 'Pray for me, pray for me!'
Rookwoode met his death on the gallows at Westminster Yard, even though he showed remorse, he was left to hang for longer than the others, a small mercy perhaps - he would be dead before they disemboweled him!