Captain Archer is delighted to welcome his mentor, Emory Erickson, who invented the transporter, along with his daughter, Danica, aboard Enterprise to conduct experiments in sub-quantum teleportation. Erickson seems to be progressing nicely in his work, until the ship enters the blackest and most dangerous area in space known as The Barrens, and a member of Starfleet is brutally killed by an amorphous shape.
When it becomes evident to Archer that Erickson lied about the true nature of his mission, Erickson confesses that his objective is to materialize his son Quinn, who was lost in a transporter-malfunction 15 years ago. Although furious with his friend for lying to him and for putting his crew in danger, Archer lends Erickson his support and allows him to carry out his dangerous mission.
With Trip's reluctant engineering assistance, Erickson is able to make contact with his son. But joy quickly turns to horror when Quinn's body materializes in a deteriorated state, and completing the transport process will surely kill him. Archer urges his friend to finally let his son go, but Erickson protests, needing to hold his son one last time to say goodbye. Stoically, Erickson completes the teleportation process and soon cradles his son's lifeless body. T'Pol, who has not yet come to terms with the recent death of her mother, is clearly affected by the touching goodbye of a father to his son.