Arrival DLC
I am playing through ME 2 again and added the Arrival DLC. I've recruited 3 of my team and still haven't had any indication of the Arrival mission. I thought the Arrival was a part of the beginning...
You get the mission after you've been to Horizon. It's not so far into the game. However, the Arrival dlc is actually the bridge to ME3, so chronologically it would be the last thing you do, even after beating the main missions. But like I said, it's available quite early on and nothing stops you from playing it as soon as you get it.
