The original storyline ends with a bit of vagueness after the two characters speak to each other but the sound is indistinguishable leaving readers wondering. In this fan fiction it picks off right before they say something including changing what they say and making it audible and essentially writing a follow up to the original plot line.
I have seen many gifsets and fics for TLOU on my dash in the past few days but I don’t really know much about it. I always love it when people write for missing dialogue! It’s so interesting to position yourself as a writer, trying to guess at what could have (or should have) been said if the dialogue was audible/understandable.