Warning: Spoilers ahead for The Last of Us season 2, episode 4, & The Last of Us Part II game!Ellie mentions the Apollo 1 mission while exploring a tank in religious cult known as the Seraphites. Though Ellie and Dina are on the hunt for Abby, they are undeniably walking into a dangerous area, and it has been that way for quite some time.

Before the events of The Last of Us, FEDRA controlled Seattle, using it as a Quarantine Zone, before the Wolves took over. Jeffrey Wright's character, Isaac, who kills his FEDRA unit to show his WLF allegiance. Remnants of FEDRA's control can be seen around Seattle by the time Ellie and Dina explore the city, including the skeletons of dead soldiers and an abandoned tank. When Ellie checks out the tank, she mentions something that will connect to an Joel episode in season 2.

Ellie's Mention Of The Apollo 1 Mission Is A Reminder Of What's Coming With A Joel Flashback In The Last Of Us Season 2

Joel Was Well Aware Of Ellie's Love Of Space

During their initial exploration of Seattle, Ellie and Dina look around the Capitol Hill area. The neighborhood seems long untouched and overgrown, but it's evident that fighting between FEDRA and the WLF took place there in the past. After coming across the tank, Ellie climbs on top and gets a look inside, where she discovers "three burnt skeletons," which instantly sets off her space knowledge, comparing it to the Apollo 1 mission. Ellie's love of space is nothing new, but it will come into play during an Joel moment in the form of a flashback episode.

Ellie mentions Apollo 1 due to the similarities between the fates of the FEDRA soldiers and what really happened to the astronauts in 1967. During a launch test for the space mission, astronauts Gus Grisson, Ed White, and Roger B. Chaffee were killed in a cabin fire while trapped inside the command module. Dina, of course, doesn't know what Ellie is referring to, though Joel may have because he has much more experience with Ellie's space obsession, especially after their trip to the Wyoming Museum of Science and History.

In The Last of Us Part II game, there's an extended flashback sequence that features Joel taking Ellie to the museum as a surprise for her sixteenth birthday. Considering the museum has an entire exhibit dedicated to space exploration, Joel knew it would be something she'd enjoy. Though Ellie already had a tendency to throw out space trivia, it's possible she learned about the failed Apollo 1 mission while at the museum. Time will tell since the museum flashback with Pedro Pascal's Joel will happen during The Last of Us season 2.

Ellie's Birthday Flashback With Joel Is Heartbreaking, But It's Important In The Last Of Us

The Museum Trip Is A Significant Chapter Of Ellie's Story

At this point, any mention or appearance of Pedro Pascal's character will be bittersweet after Joel's death in The Last of Us season 2, episode 2. However, the flashback involving the museum trip is more heartbreaking since it features a time when Ellie and Joel were still very close. By the events of The Last of Us season 2's time jump, Ellie and Joel have a very strained relationship, so the birthday celebration will return to a time when their bond was at its strongest, and they still had a future together.

While The Last of Us probably wouldn't up any chance to bring back Pascal's Joel, the museum flashback is significant for several reasons. Aside from allowing Ellie to share some of her ions with Joel, including geeking out while inside a space capsule, the flashback proves just how much Joel meant to Ellie despite their eventual falling out. The flashback will act as a memory of one of her best days with Joel while she's still at her lowest in Seattle.

The museum trip set for later in The Last of Us season 2 also teases why Ellie becomes so mad at Joel down the line. While at the Wyoming Museum of Science and History, Ellie finds a Firefly who died by suicide, as well as Firefly graffiti that includes their symbol and the word "Liars." Ellie has questions, but Joel tries to steer her away from anything Firefly-related. Not long after the museum trip, Ellie learns the truth about what Joel did to the Fireflies in Salt Lake City. Still, it seems her special memory with Joel involving her love of space hasn't left her.