[2] He obtained a prebend in the prebendary of the church of York, and was later promised the mastership of the Hospital of St Cross, near Winchester, by Queen Elizabeth.
Brooke and Sir Griffin Markham persuaded themselves that if they could get possession of the royal person they would have it in their power to remove the present members of the council, compel the king to tolerate the Roman Catholics, and secure for themselves the chief employments of the state.
Brooke was arrested and sent to the Tower of London for his involvement in the Bye Plot in July 1603; he was arraigned on the 15th.
Brooke appears to have hoped to the last to obtain a pardon by means of Cecil, who had married his sister.
Brooke, in fact, alone of the lay conspirators suffered on the scaffold in the castle yard at Winchester, Hampshire, on 5 December 1603, executed for high treason.