S04E06: 'The Other Woman'

In a series of flashbacks, it is revealed that Juliet is the object of Ben's obsession. When she arrives on the island, Juliet becomes friendly with Goodwin, the husband of her stern therapist Harper. Once Harper discovers the affair, she warns Juliet that Ben will not be pleased. When the plane crashes on the island, Goodwin is sent to infiltrate the tail section and ends up being murdered by Ana Lucia. Ben takes Juliet to his corpse and tells her that she is his property.

In the present, Charlotte and Daniel sneak away from Jack's group clutching a bag with gas masks. Kate confronts them on the way, but Charlotte knocks her out. Harper appears in the rainy jungle and tells Juliet that the duo intends on releasing a lethal gas from a place called the Tempest. Juliet finds them there and pulls a gun on Daniel. He claims that he is merely making the gas inert and ensuring that Ben can't use it as a weapon in the future. Outside the Tempest, Juliet and Jack share a lingering kiss.

Ben manages to strike a deal with Locke. In return for a limited amount of freedom, Ben shows him a video tape hidden in a safe in his house. It depicts Charles Widmore and Ben tells Locke that Penelope's father is the man in control of the 'rescue' boat and is intent on using the resources on this island for his own commercial gain.