Trip has butterflies as transporter inventor Emory Erickson, his inspiration to become an engineer, comes aboard. Erickson beams aboard in a wheelchair attended by his daughter Danica. Erickson "borrows" NX-01 to an empty range of space called The Barrens, to test a new subquantum transporter claimed effective across interplanetary ranges. (Lessee, bright black engineer beams aboard threatening to put captain out of work. Got it.) T'Pol wants to spend more time reading the Kir'Shara and less with Trip, discussing dead family members or anything else. At dinner they all toast Henry Archer.

Later Trip guts the transporter and discusses the device's early history; Erickson was left with a twisted spine, living proof of the risks. Though Trip tries to be pleasant, Erickson blows him off. Danica confesses to Archer her father never got over his son Quinn's loss, then returns to stick him in the back with a nasty-looking needle, insisting they tell Archer the truth. She says they should seek his help, but Erickson worries a Starfleet Captain's first duty is to his ship (not the truth?). Some sort of spatial anomaly causes a power surge on F-deck and a sparkly being lethally touches a crewman inducing cellular disruption (read: gnarly face) like delta radiation.

Trip and Erickson successfully materialize a probe 40000 km away. Trip offers to celebrate but is rebuffed again. He begins to disbelieve Erickson, as does Archer, discovering something similar in Erickson's past. Another anomaly hits C-Deck; T'Pol ignores the no-touch warning and gnarlifies her hand. She snapped a picture and after enhancement Archer recognizes the "anomaly" as Quinn. Emory admits he's not testing a new subquantum transporter; fundamentally flawed, it doesn't work. During trials fifteen years ago it sent Quinn's signal off to The Barrens. Archer's angry Erickson didn't trust him but crankily orders a reluctant Trip to help. Danica apologizes to Archer but refuses to pet Porthos.

T'Pol informs Trip she's found new priorities, cooped up reading her Bible. Quinn 's signal causes an explosion; Archer saves Emory's life. He offers a pithy "Don't fail" to Erickson's self-doubt. They anticipate Quinn's reappearance but despite cross phasing streams (and new terminal?) the transporter fails to acquire Quinn intact. Phlox reports massive damage though he beams in looking fine, dying in his father's arms. Erickson came to bring Quinn home and achieved his goal, and now awaits punishment. Phlox says T'Pol's Pa'nar is cured but she never FELT less certain so who knows? Danica says maybe she'll see Archer around as they depart for home.