There’s a lot of satisfying places that still could’ve been brutal and bittersweet. The theme of the first was about finding hope in even the most bleak settings. You could even say it’s about people lost in the darkness still looking for the light

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Tommy says in the opening he’ll take the secret about Joel wiping out the fireflies to the grave if needed. Clear foreshadowing. Abby and her friends could’ve been more interested in answers about what went down in Salt Lake City (Abby would have had no knowledge of Ellie in this scenario). They go looking for Tommy since they know he used to be a firefly and he refuses to tell them anything a shootout happens and Tommy is either captured or killed so Ellie decides to go after them after she finds a WLF patch. Joel reluctantly agrees, which leaves Ellie suspicious about things and along the way they find enough that suggests the issue is stemming from their efforts to find a cure still. At some point Ellie calls Joel out on his lie so he finally tells her while they’re out there. They would eventually find Tommy (if he’s still alive) but the escape from Seattle goes wrong somehow and only one of Joel or Tommy makes it back with Ellie. The game would end with something like the nighttime porch conversation that Ellie and Joel have except it’s in real time and not a flashback so the moral or message here would be that Ellie has to learn that her life has value on its own and it’s ok that she doesn’t save the universe.
That sounds like a story that holds some really heavy beats but stays true to the themes of the first game