Lancelot and Guinevere (S02E04)

Gwen is wrongly identified as Morgana and captured by the ruthless outlaw Hengist. When Uther declines to pay the ransom, Arthur goes against his father's wishes and ventures into perilous enemy lands to rescue Gwen. Merlin senses that Arthur's feelings for Gwen run deeper than mere loyalty to a subject. However, Arthur's journey takes an unexpected turn when he learns that Gwen is not by herself in Hengist's fortress—she has reunited with Lancelot, and their intense emotions are reignited.