The Walking Dead: 400 Days will serve as "connective tissue" between the first season of the game and the second. The DLC will be about the same size as a normal episode of the game but will be broken down into five different stories which occur at various points during the first 400 days of the zombie outbreak.
Each story will focus on a new character but all of them will somehow connect to the Atlanta truck stop from the first game. As you would expect the decisions you make in the DLC will impact what happens in Season 2 of the series but what you might not expect is that the decisions from the first season will impact what happens in the DLC. The TellTale team was mum on what those could be so we'll have to wait for the game to be released next month to find out.
The short presentation we saw at E3 featured Vince, a man who apparently kills someone at the start of the episode and is captured, convicted, and sentenced to jail time. I use the word apparently because this is The Walking Dead and things are never as they seem. Vince's story occurs on the second day of the outbreak and we find him on a prison bus with several other prisoners.
As Vince chats with some of his fellow guests we learn more about them and the crimes they were accused of. One prisoner is a white collar criminal who swindled $180M before being caught while the other was convicted of illegally touching a minor. We also learn that the prisoners have been stuck in the hot Georgia sun conflict in a bus with windows that don't open. As the conversation between Vince and his companions continues, the heat gets to two prisoners and as you would from a Walking Dead property people start dying and then coming back to life.
The tension of being confined to a prison bus with a flesh eating zombie is amplified significantly by the fact that Vince and his companions are chained to the floor. The game immediately forces you to make difficult decisions about who lives and who dies and it's all classic Walking Dead drama.
From what I saw it looks like 400 Days is going to be a great transition between the two seasons. The writing is spot on and it leverages all of the familiar tropes of the Walking Dead universe. It's also a subtle reminder for people like me that I need to go back and finish the first season of the game.