The episode aired on February 23, 2010, on ABC in the United States and 2 hours earlier on A in Canada due to the 2010 Winter Olympics.

[2] The episode was written by showrunners and executive producers Damon Lindelof and Carlton Cuse and was directed by Jack Bender.

In 2007, the ghost of Jacob (Mark Pellegrino) instructs Hugo "Hurley" Reyes (Jorge Garcia) to bring Jack Shephard (Matthew Fox) to an unspecified place.

Meanwhile, Jin-Soo Kwon (Daniel Dae Kim) finds Claire Littleton (Emilie de Ravin) after 3 years of disappearance, but begins to question her sanity.

Jack runs into Dogen (Hiroyuki Sanada), another parent at the event, who praises David's skill and believes he has a gift.

Along the way, Jack and Hurley encounter Kate Austen (Evangeline Lilly), who refuses to go with them to continue her search for Claire.

Meanwhile, Jin-Soo Kwon (Daniel Dae Kim) is rescued by Claire from her trap, taking him and injured Other Justin to her hideout.

She treats Jin's leg injury and then threatens to kill Justin unless he reveals the location of her son Aaron.

[3] Chris Carbot of IGN gave the episode a positive review, saying "Lighthouse isn't filled with the wall-to-wall excitement of last week's Locke-centric story but it still has plenty of great moments and surprising revelations."

"[7] Variety's Cynthia Littleton praised "Lighthouse" for having "a heavy old-school "Lost" vibe" and the flash-forwards starting to make more sense.

Maureen Ryan of Chicago Tribune thought, "If I have any recurring complaint this season, it's this: A great episode of 'Lost' works as an hour of TV.