You think you've seen it all. You called what the strangers you met in episode 2 were "up to", who was the traitor in episode 3, and even managed to guess Doug's favorite pie flavor.
But then, out of nowhere, Lee dies. The main character you've built up to your own moral standards by precariously choosing the tough decisions that the game threw at you is suddenly wiped off the face of the earth. Episode 4 and 5 are about you playing as Clem, but FIFTEEN YEARS in the future. Clem grew up adopting what she learned from Lee, and now you're the only one left of the original group, struggling to survive in a world that has become increasingly harsh.