By early 1812 Knowles has purchased a captaincy in 45th Regiment of Foot, but is on hand to assist Lawford when the latter is seriously injured during the storming of Ciudad Rodrigo (Sharpe's Company). Knowles sympathises with Sharpe when he learns that his mentor has been demoted from captain to lieutenant and promises to protect Sharpe's lover, Teresa Moreno, who is trapped with her young child in the besieged city of Badajoz. Subsequently, Knowles takes part in a successful escalade of the castle at Badajoz (in this Cornwell has borrowed the real life achievement of a Lieutenant James MacPherson). He then seeks out Teresa, but is shot and killed by Obadiah Hakeswill.