HBO's hit series just ended its first season with a simple, yet very impactful conversation between Ellie and Joel. And while the reaction of both may seem normal, the things left unsaid speak volumes about the brewing tension and conflict between the two. Along with that tense ending are tons of cool details and trivia that will make the latest installment a lot more awesome. Here are the best The Last Of Us episode 9 easter eggs you must know about.

5 The Last Of Us episode 9 easter eggs

5. Anna and how Ellie became immune

The Last Of Us episode 9 starts with a flashback as a pregnant woman named Anna enters an abandoned house outside of any Quarantined Zone. After seeing that the people she was expecting weren't there yet, Anna resigns herself to an empty room to wait. At that moment, a lone infected individual bursts through the barricaded door and bites her leg before being incapacitated by Anna. Quickly after, she gives birth to her baby and immediately cuts the umbilical cord to prevent the infection from taking the child.

After a few hours, Marlene arrives with her Fireflies and finds an infected Anna with a baby named Ellie in her arms. She gives the child to Marlene and asks her friend to find someone who can raise her up while promising that Ellie hasn't been infected in any way. And while she initially refused at first, Marlene gave in and killed Anna before the infection fully took her body.

Later on, Marlene would go on to explain to Joel how Ellie got her immunity. She says that the doctors hypothesize that the cordyceps grew up with her, producing a chemical messenger that makes the fungi think a normal variant of itself resides within her body. This development, of course, came about when Anna suddenly gave birth to her after getting bitten by an infected. As a result, the young girl became the only known immune individual to the infection. Also, the actor who portrayed Anna is Ashley Johnson, the same person who gave life to Ellie in the video game by means of her voice and motion capture performances.

4. Ellie and Joel's journey to Salt Lake City

Back in episode 1, Joel started his journey with Ellie in Boston. After eight episodes, several locations in which they stopped over, and a couple of near-death encounters, the pair finally reach their destination when they find the Firefly hospital in Salt Lake City, Utah. Doing the math, Joel and Ellie just traveled 3,500 miles across the United States to get to the end of their journey.

But before they can find the Fireflies' hospital or any of their people, Ellie finds a thriving patch of land filled with lush greeneries and a herd of giraffes. This discovery mirrors what happened in the Naughty Dog video game as the pair also find these mammals in Salt Lake City before reaching the Fireflies.

3. Joel's moment of vulnerability

Before Joel and Ellie could locate the Fireflies' hospital, the latter spends a quiet moment with the young girl to explain where he got the scar on his head. Shortly after Outbreak Day and Sarah's death, Joel tried to kill himself with a gun and missed, causing a scar to form on his head. Ellie responds that time heals all wounds. For his part, Joel implies that his newfound love for Ellie as a surrogate daughter helped him get out of the darkness he has been living in for the last couple of decades.

Rather than converse about their strengthened bond further, Joel asks Ellie to read him more jokes from her pun book, an idea to which the young girl happily obliges. This moment differs from the game as Ellie shows Joel a photo of Sarah she stole from Jackson. This leads Joel to get a bit emotional and thanked the young girl after. As can be seen in the HBO series, the moment itself was changed and expanded to build upon the latter part of the episode to give the season finale more weight and impact.

2. A cameo from The Last Of Us II

After Marlene's explanation about how a vaccine can be created by killing Ellie, Joel is ordered to be taken away to prevent him from interfering. Rather than go through the loss of another daughter-like figure in his life, Joel goes full Rambo on the Fireflies and takes them out one by one until he reaches an unconscious Ellie on an operating table.

At this point, Joel takes out the doctor who was about to stab him with a scalpel. He then orders the two remaining female nurses to release Ellie into his care right away. One of these nurses is played by Laura Bailey, the same actress that voiced Abby in the video game and gave her life via motion capture.

1. Joel's answer to Ellie's question

With Ellie back in her care, Joel lies to the young girl about what truly happened inside the Firefly hospital. He tells her that the Fireflies already have immune individuals in their care and they are still unable to produce a vaccine from them, causing Joel to take Ellie and leave.

Right before reaching Jackson on foot, Ellie confronts Joel and makes him swear that he told her the truth. After a short moment of hesitation, Joel swears and tells her that what he said was true. Even with doubt in her eyes, Ellie accepts Joel's answer as the first season concludes on that note. Again, this scene mirrors what happened in the first game as it ended in a similar manner.

While The Last Of Us season 2 is confirmed, there's no word yet on the exact release date. It's best to stay tuned for details as to when this hit HBO series will come back in the future.