Ep 18. Heart of Gold

Emma and Regina team up to track down Robin Hood, who they believe has betrayed them and stolen something important to Regina. As they follow his trail, they encounter a woman named Zelena, who claims to be Robin's wife and the mother of his child. Zelena offers to help them find Robin in exchange for their help with a problem she's facing - someone has been trying to kill her.

Meanwhile, in flashbacks, we see Robin's history with a woman named Marian, who he fell in love with and married in his homeland. When an old friend arrives to tell Robin that Marian is sick and dying, he makes the difficult decision to leave his wife and child behind and head to Storybrooke to find a way to save her.

As the two storylines intersect and secrets are revealed, Emma and Regina must decide whether or not they can trust Robin and Zelena, and whether their own desires for love and family are worth sacrificing for the greater good.