Locke is enlightened as to the whereabouts of Jacob's cabin, and life aboard the freighter becomes perilous. Guest starring are Jeff Fahey as Frank Lapidus, Lance Reddick as Matthew Abaddon, Marc Vann as doctor, Kevin Durand as Keamy, Anthony Azizi as Omar, Grant Bowler as Captain Gault, John Terry as Christian Shephard, Holland Roden as Emily, Rebecca Tilney as Emily's mother, Amanda Carlin as ER nurse, Patrick Torres as ER doctor, Doug Hutchison as Horace Goodspeed, Nestor Carbonell as Richard Alpert, Matthew Pedersen as physical therapist, Mandy June Turpin as Florence, Sarah Duval as Melissa, Charles Henry Wyson as John Locke (age 5), Phil Abrams as Gellert and Caleb Steinmeyer as John Locke (age 16).Clippage! * We return this week to flashbacks, and how. I’m guessing we go farther back with each flash. * Young Locke will get a proposition from a high school chemistry teacher. * Younger Locke will spend some time in a school locke-r. * Youngest Locke may meet Richard Alpert. ****SUPERSPOILERS BEYOND TONIGHT’S EPISODE FOLLOW**** ****DO NOT READ BEYOND THIS POINT**** Alpert is in next week’s episode too. Widmore’s freighter fiends, as one might guess, do not rescue the Oceanic Six. Desmond may come very close to becoming one of the Oceanic Seven. The finale will depict the arrival on the American mainland of the Oceanic Six, as well as the funeral of Christian Shephard. And we’ll learn more about why Jack is so hot to return to Dharma Island. Next week we get what’s being billed as the first hour of a three-hour season finale. Then you have to wait two more weeks to get season four’s final two hours. Then you’ll have to wait at least seven months for the next episode after that. 10 p.m. Thursday. ABC.