1. Takes place in The Beginning of the End, Season 1 Episode 8.
When Morgana says, "What if magic isn't something you choose? What if it chooses you?" Merlin tells her about his. Then, using Merlin's magic openly and with Morgana's help, they successfully get Mordred out of Camelot. Morgana is determined to stay with Mordred after they find the druids, and Merlin allows himself to feel all the things propriety and destiny have forbade. Merlin and Morgana raise Mordred as a son and Merlin ascends into his rightful role as Emrys. But Camelot and Arthur cannot stay safe forever.