In a flashback, we meet Anna, Ellie's mother.

She runs out of a clearing as she's being pursued by the infected. Heavily pregnant, she rushes into a house, goes upstairs and attempts to hide.

She locks herself in a room but starts giving birth. An infected gets in and she stabs him as she gives birth.

She then realizes she's been bitten and holds a knife at her head until people can get to her and get her daughter.

Marlene arrives and she says that she was bitten after child birth so Ellie is not infected.

Marlene takes Ellie and tries to escape the house but Anna makes her promise to kill her.

Marlene shoots her in the head.

In the present, Joel and Ellie are making their way to the hospital and the fireflies.

They go into a building and Ellie rushes off --- because she sees giraffes. The two of them work together and feed the giraffes.

When they leave, Joel tells Ellie about his suicide attempt and how he flinched at the last minute, and that helping Ellie might be his reason for it.

A grenade appears and knocks them both out. Joel wakes up in a hospital with Marlene over him.

She says that Ellie is being prepared for surgery and that she never wanted to be indebted to Joel.

She says that Ellie will die with the surgery because her brain could be the trick to saving the world.

Joel is led away from the hospital but he goes rogue and kills Marlene's men. He rushes through the hospital with guns, killing everyone in his sights, until he gets to the operating room.

The surgeon tries to plead with him but he shoots him in the head and demands that the nurses give Ellie to him.

He rushes out of the hospital and is stopped by Marlene. He shoots her once. She pleads for her life and he says he can't because she will come after him. He kills her.

Ellie wakes up in the car, shocked, and Joel says the hospital was attacked by raiders and that there are others like Ellie. She's sad to know that Marlene died.

When they get to Jackson, Ellie tells Joel about Riley and how she died.

She then asks Joel to promise that what he said about the hospital was true. He says it.