The trailer for HBO's The Last of Us show featured an amazing but easy-to-miss Easter egg to its video game source material. HBO recently released the first full trailer for the show, based on Naughty Dog's eponymous video game franchise. Much like the game, the show focuses on Joel (Pedro Pascal), a smuggler hired to take a young girl named Ellie (Bella Ramsey) out of a quarantine zone in a post-apocalyptic future where humanity was plagued by the outbreak of a Cordyceps virus, which mutated people into zombie-like creatures. Partly developed by The Last of Us director and writer Neil Druckmann, HBO's The Last of Us aims to present a new take on the franchise, adapting the games relatively faithfully while still providing its own spin on them.

HBO's The Last of Us trailer featured several callbacks to recognizable moments from its game counterpart, such as Joel escaping with his daughter, Sarah, on Outbreak Day and Ellie spending the day in an abandoned mall with her best friend, Riley. The trailer's premiere date was also an Easter egg in itself, being released on September 26, the same day that the Cordyceps outbreak occurred in the game. However, arguably the trailer's best Easter egg was its choice of music. The song featured in it was 1951's "Alone & Forsaken," by Hank Williams, which was also used for The Last of Us trailer released during Gamescom 2012. The trailer began with Ellie handing Joel (voiced by Ashley Johnson and Troy Baker, respectively) a cassette of the song as they drove, after which it began playing over the game's footage.

Related: Every Way HBO's The Last Of Us Will Differ From The Games

The song was also featured in the game itself, as Ellie and Joel drove into Pittsburgh before they were ambushed by a group of hunters. It was further referenced via the first level in the "Pittsburgh" chapter, titled "Alone and Forsaken." The trailer for HBO's The Last of Us presented a slightly different take on the song, making it slightly more somber and repeating the line "Please hold to my hand" multiple times near the end. The lyric is directed at God, as the song's protagonist laments his loneliness and abandonment after separating from his partner. Aside from being a Last of Us game Easter egg, the song aided in conveying the desolate and hopeless nature of the series.

Why Hank Williams' "Alone & Forsaken" Is Perfect For The Last Of Us

HBO The Last of Us Pedro Pascal and Bella Ramsey as Joel Miller and Ellie Williams

The Last of Us trailer's musical Easter egg is particularly poignant due to "Alone & Forsaken" being so perfectly suited for both the game and its live-action adaptation. The Last of Us is not an optimistic story. It's a bleak exploration of the worst of humanity and how far people are willing to go in desperate situations. This is perhaps best depicted through Joel, who, despite being one of the game's protagonists, is not an entirely good person. As it's revealed throughout the story, he did many morally reprehensible things following the outbreak to survive. His partial redemption in The Last of Us game came in the way of Ellie, who helped him regain some of his humanity. Yet, even with that, he was never fully able to escape his violent tendencies, evidenced by him murdering countless people at the end of the game in an effort to save Ellie.

As such, "Alone & Forsaken" is an apt representation of the game's bleak nature. The song is about a man who's left by a loved one but it is the themes of abandonment and hopelessness that make it a perfect fit for the themes explored in The Last of Us. The trailer ends with the lyric, "Oh, please understand." The lyric perfectly encapsulates the moral message of the game. The Last of Us forces players to sympathize with a man who did terrible things. It asks them to understand his actions, showing that, though unforgivable, they were done with the intention to survive and not out of pleasure. With that, the last line in the trailer once again showed why "Alone & Forsaken" is so appropriate for The Last of Us universe. HBO's The Last of Us will put its own spin on its source material, but as the trailer and its musical Easter egg showed, the series seems to have perfectly captured the games' essence.