The accident in which Quinn Erickson, son of the transporter's inventor, was lost during a sub-quantum teleportation test, and his father's attempt fifteen years later to bring him back.
Quinn Erickson vanished about fifteen years before the Enterprise episode Daedalus while testing sub-quantum teleportation, a method his father Emory Erickson hoped would make it possible to beam across vast distances. The test took place in the Barrens, a region empty of stars, and Quinn's pattern was left trapped in subspace.
In 2154 Emory, by then celebrated as the father of the transporter, comes aboard Enterprise NX-01 with his daughter Danica. He tells his old friend Jonathan Archer that he wishes to try the new technology again, when his real aim is to recover his son.
A distorted form of Quinn appears on the ship and kills a crewman. Archer, angry at the deception, still helps, and Quinn is rematerialised, but he dies moments later in his father's arms.