It says much of the quality and depth of The Last of Us' characters and world that Naughty Dog could have picked any one of a number of threads to explore in this, the first and only story expansion for its seminal action-adventure. The strained relationship between Joel and his brother Tommy; Marlene's journey from Ellie's guardian to head of the Fireflies; the story of Ish, the enigmatic survivor whose notes detail his harrowing experiences in Pittsburgh - any might have worked.
Instead, Neil Druckmann, Bruce Straley and their team have chosen to explore one of the defining relationships of our young heroine Ellie's life - her close friendship with a fellow teenage survivor, Riley. Those that have played through The Last of Us already know how this story ends and likely have an idea of how it might play out, and so it is to the developer's significant credit that Left Behind manages to defy foreknowledge to tell a story that is touching, revealing and important.
Left Behind presents an unexpected duality, contrasting the Ellie with whom we are familiar with one whom we've never met. Ostensibly, it is a snapshot of a pivotal time in Ellie and Riley's friendship that plays out against the backdrop of a post-outbreak world, a world in which quarantine zones and death are everyday considerations and where trips to the mall and carefree teenage frivolity are wholly alien concepts. To pick out any single instance of this juxtaposition would be to deny you the joy of discovery. Suffice to say that exploration is its own reward, and it's as amusing as it is poignant to witness the two friends walk amongst the relics of an opulent past and wonder aloud at the bemusing superficiality of it all.
In its way, Left Behind also serves as an examination of Ellie's later relationship with Joel. It offers insight into the depth of the bond that exists between the two and provides a deeper understanding of this relationship by exploring events that are only alluded to in the main story. In doing so, it once again turns the pseudo-father-daughter relationship on its head and offers still more to ponder in the main story's ambiguous ending. While there's certainly value in playing through The Last of Us again prior to starting Left Behind, there's also a surprising amount to be taken from venturing through the main story once more after experiencing this DLC, in possession of the knowledge that it brings.
One of The Last of Us' key strengths is how its mechanics are imbued with a sense of purpose and tied so wonderfully to the narrative. Left Behind furthers this dynamic - you never feel that Druckmann, Straley and co are frustrated novelists or film directors. There's still that same tangible context that justifies searching every room and rummaging in every drawer, and Left Behind progresses this technique tying exploration of a space with exploration of the story by connecting some conversations and minor details to your performance in certain tasks. It doesn't change the story in any meaningful way, but it adds some diversity and dynamism.
This is furthered by Left Behind's small but important advancements in combat, which see infected and hostile enemies clash with each other, giving rise to emergent moments that are instigated and influenced by your actions. You can creep past all of your foes or try to take them all down stealthily, but the most satisfying and natural course of action is to lead one faction to the other and let them fight it out.
There'll be survivors of these clashes, of course, so the game becomes about manipulating the scenario to ensure that the group you prefer to face come out on top. It's a shame that there aren't more incidental animations for the infected, as they will often stand around seemingly waiting for something to happen, but it's a minor quibble.
Nonetheless, it's good to revisit a combat model that forces you to think on your feet and to go up against AI that doesn't settle for holing up behind cover or taking pot-shots from afar. As before, the amount of ammo and crafting material available for use in combat is dictated by the difficulty level, and playing on normal difficulty means that you'll seldom be left wanting for these commodities. It can undermine the thrill of survival to have such an abundance of health and ammo pick-ups, but as you're likely going to want to play through Left Behind a second and even a third time, you can try out the different difficulty levels to appreciate how the experience varies. It's a personal choice, but I'd recommend a first run-through on Hard difficulty and then, for the second, Survivor, where you truly get the sense of environments picked clean and, combined with Ellie's pared-back arsenal, the importance of making every shot or stealth-kill count.
"In one or two crucial instances, Left Behind defies its stature as an optional add-on by managing to broaden the horizon of the medium as a whole."
Talk of multiple play-throughs leads inevitably to the question of value for money. Left Behind costs £11.99 on its own or £15.99 as part of The Last of Us season pass, and my initial play-through on hard difficulty, in which I unearthed every collectable but missed some of the incidental conversations, came in at two and a half hours. The key difference between this experience and that offered by the likes of the similarly-timed Burial at Sea: Episode One expansion for BioShock Infinite is that Left Behind is much more densely packed and altogether better paced. Every beat is dedicated to driving the story forward, setting up engaging combat scenarios and revealing meaningful details of relationships past and present. In one or two crucial instances, Left Behind defies its stature as an optional add-on by managing to broaden the horizon of the medium as a whole.
What this amounts to is a beautifully crafted addendum to The Last of Us, a game that already stood tall above many of its peers. While it could have benefited from yet more exploration, its impeccable level design utilises its environments to take Ellie and Riley - wonderfully portrayed by Ashley Johnson and Yaani King - on a trip that is not easily forgotten, underpinned by sparing use of Gustavo Santaolalla's beautiful score.
Left Behind deftly avoids falling foul of clichéd convenience or too-cute contrivance to deliver time and again throughout its short duration. It's so easy to want more of this world - either in the form of a longer run-time here, the chance to explore more of its stories as DLC, or even to hope for a full-blown sequel - but should Naughty Dog resist and lay to rest the stunning experience that it has created, Left Behind will serve as a fitting and masterful final farewell.