Dana Scully plays host to her parents for the Christmas Holiday. Her father (played by Don S. Davis, who would later go on to play General Hammond on Stargate SG-1) never approved of Dana's choice to become an FBI agent. Regardless of this underlying tension, the visit is pleasant enough, and after they leave, Scully falls asleep on the sofa in the living room. In a chilling scene, Dana wakes up on the living room sofa to see her father mysteriously sitting on a chair, speaking to her, yet not a word he is saying can be heard. The phone rings, momentarily diverting Dana's attention, and when she glances back at the chair, she is startled to see that her father has vanished. Dana receives a further shock when the phone calls turns out to be from her mother, who tells her that her father had just passed away.

After attending the funeral, Scully joins Mulder on a new case. Two collage students had just been abducted. A year previously, two other students--also a boy and a girl--had been kidnapped and murdered after five days. If this is the same killer, then Mulder figures that they have five days to rescue his latest victims. But there's a catch this time. Luther Lee Boggs (played by Brad Dourif in a captivating performance), a convicted serial killer who was put away by Mulder, claims to know where the new victims are and is willing to talk--in exchange for a stay of his impending execution. Boggs claims to have psychic powers, which enable him to see beyond the prison walls, but Mulder does not believe him. He thinks Boggs orchestrated the kidnapping with somebody on the outside. However, when she is briefly left alone with Boggs in the interrogation room, Scully is stunned when Boggs tells her something that only her father would know. This causes her to privately investigate Boggs' vision of where the killer had stashed his victims, and while the killer had already moved the students to a new hideout, it turns out that Boggs had been correct; the killer and his victims were exactly where he said they would be.

What's amazing about Beyond The Sea (which is named after the old song; a favorite of Scully's parents) is that the usual roles of believer and nonbeliever are reversed: this time, Scully is the believer, while Mulder is the doubter. He keeps warning Scully not to get too close to Boggs, for the crafty serial killer may well be planning one last killing just before he is sentenced to pay the ultimate price for his crimes. Superbly written by Glen Morgan and James Wong, and tightly directed, this episode is very dark, scary and gripping. The tension of the main storyline is matched by Scully's inner turmoil as she grapples with the supernatural while tangling with a pair of very real and dangerous murderers. This is an outstanding episode that shows to great effect that The X-Files was far more than just a "monster of the week" show.