On the latest "Once Upon a Time," Gold and Pan revisited unresolved issues and Henry gave one character a major gift.

In "Think Lovely Thoughts," Pan (Robbie Kay) tells the Lost Boys that Henry is willing to do whatever he can to bring magic back to Neverland.

Meanwhile, everyone is looking for Henry. Gold (Robert Carlyle) tells the others that Pandora's Box will trap Pan if he opens it. Neal (Michael Raymond-James) still doesn't trust Gold, so Gold hands the box over to Neal. Gold also reveals that the evil Pan destroyed his own father.

Emma (Jennifer Morrison) tells Hook (Colin O'Donoghue) that they need to save David. Gold overhears, and tells them that they can save David in Storybrooke with an elixir from this shop.

Meanwhile, the gang finds Pan's camp. The find Wendy in a cage, and she has a reunion with Neal, even though she doesn't recognize him. Wendy says she came to Neverland to save Neal. She reveals to them that Pan is sick, and that the only way he can be cured is by taking Henry's heart, which would kill Henry and render Pan immortal.

Pan and Henry reach Skull Rock, and Pan draws a line in the sand as a protection spell. When the heroes reach Skull Rock, Gold is the only one who can cross the line because he doesn't have a shadow. Regina (Lana Parrilla) is miraculously able to block out the moon's light, which eliminates their shadows.

It's then revealed in a shocking plot twist that Pan is Gold's father. Gold then uses Pandora's Box on Pan, but Pan has switched the boxes. He turns Gold into red smoke, then Gold gets sucked into the real Pandora's Box.

Pan then goes to Henry and tries to convince Henry to pull out his own heart. Just as Henry is about to do it, the gang tells Henry that Pan is tricking him. But Henry is convinced that he needs to save the island's magic, so he puts his heart into Pan's body. Henry falls over unconscious, and Pan floats above them all, relishing his newfound power.

It's revealed in a flashback that Gold's father, Pan, let the Shadow take Gold, his only son, so he could become a young boy again. Gold's dad turns into none other than Peter Pan.

On the next episode, "Save Henry," "While Henry's life hangs in the balance, the race is on to stop Pan from gaining full magical powers from the heart of the truest believer. Meanwhile, in Storybrooke of the past, Regina decides to fill a void in her life and, with Mr. Gold's help, sets out to adopt a baby."

Watch the promo for "Save Henry," which airs Sunday, Dec. 1 at 8 p.m. on ABC.