He even explains that Mulder's father gave over Mulder's sister Samantha to the aliens as a guarantee of their honor. CSM truly believes that what he did saved millions of lives and ultimately would bring Samantha and other family members back home. It was Mulder's father who thought of the idea to use the alien fetus DNA to make a secret vaccine against the Black Oil. Jeffrey Spender pays a visit to his father in the Syndicate offices, only to find Krycek in the now abandoned space. Krycek tells Spender that everyone has left for El Rico Air Force Base to receive the hybrid genes and that Spender's father, CSM, has gone to get Cassandra to turn her over to the aliens.
Spender informs Scully.
Meanwhile, Mulder and Diana, who has returned to her apartment, leave for the base. Mulder calls Scully to have her meet them there. Scully tells Mulder about Cassandra and the two rush to intercept the train. The train plows through their car as they escape the impact. Diana joins the Syndicate in the hangar at the base, and Cassandra is brought in.