Sony and Naughty Dog have today released the first downloadable content for The Last of Us, dubbed The Last of Us: Left Behind.

The DLC explores the experiences of Ellie that lead into the events of The Last of Us, as we’ll get to see how her relationship with Riley, her best friend and mentor develops.

According to Naughty Dog, Ellie and Riley are in military boarding school in Boston after the infection, and have will have to choose between fighting for a rebel group called the Fireflys or stay in the quarantine zone.

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Game Director Bruce Straley said, “With Left Behind, we sought to flesh out the moment that transformed her into the Ellie you knew in The Last of Us. It is the story of the complex bond with her friend Riley and how the two end up on a fierce journey that will forever change their lives, giving new insight into Ellie’s character.”

The Last of Us: Left Behind is available for digital download today on the PlayStation Store for $14.99. Season pass holders of The Last of Us will receive the Left Behind story expansion as part of their subscription.