Introduced in ‘Patient X’ Agent Spender appears to be just one of the many young agents trying to make a career in the Bureau. However, we soon learn that not only his mother claims to have been abducted by aliens (she then disappears without a trace at the same unexplained event which Agent Scully miraculously survives in this episode), he is also the son of the Cigarette-Smoking Man (‘The End’), who makes him his protegé. Being at odds with Mulder from the beginning, this worsens until in ‘The Beginning’ Agent Spender is handed over the X-Files (together with Agent Fowley) after they are re-opened, while Mulder and Scully are forbidden to investigate X-Files cases. This seems to be the work of the Cigarette-Smoking Man. Spender is clearly betraying Agent Scully’s confidence in ‘Triangle’ when he reports her request for satellite intelligence data to A.D. Kersh. In 'Two Fathers / One Son' we finally learn of the background surrounding the abduction of Cassandra Spender. While at the beginning, Agent Spender is still working for his father, the CSM, he is unable to kill a member of the faceless rebel aliens, as his father demands of him. Later, when he learns more of his father's involvement into his mother's abduction and the 'project', he turns against him and rescues Marita Covarrubias from the quarantine facility. He advises to re-assign Mulder and Scully to the X-Files and is apparently killed by his father before being able to resign as he planned.