Mass Effect 2 to 3: Bridging the Gap
Not long after the Overlord DLC was released, BioWare Creative Director Casey Hudson mentioned that they had numerous DLC packs in the works that would bridge the story between Mass Effect 2 and Mass Effect 3. This number was later clarified via a twitter post to be three separate packs, the first of which was Lair of the Shadow Broker. Even though Lair of the Shadow Broker acknowledged your completion of Mass Effect 2's Suicide Mission, it did very little other than some table setting for the exposition of Mass Effect 3. It appears that the mysterious second pack has either been scrapped or absorbed into the third, simply dubbed Arrival.
SPOILER WARNING: Just as I mentioned on the hub page, watch out if you haven't completed these or want to stay spoiler free!
Lair of the Shadow Broker is the first "bridging" DLC content for Mass Effect 3 and revolves around Liara T'Soni's hunt for the titular Shadow Broker. After you confront the Shadow Broker and Liara assumes his position, you gain two extra sequences. One revolves around her visiting your cabin, in which she talks about the future, although this tends to be more personal.
The other conversation takes place aboard her ship on Hagalaz, where she directly discusses the imminent Reaper threat. She mentions how the Shadow Broker was apparently very aware of the Reaper's cycle of destruction and was probably looking for ways to conquer them or even just survive their genocide.
Beyond these two sequences, there really isn't a lot of direct reference to the third game, only just some place-setting information. It could be inferred that Liara will use her new information network to maybe supply Shepard with a way to counteract the Reaper threat. What exactly that could be is anyone's guess. A lot of people seem to think that Liara's new responsibility will undoubtedly omit her from the party in Mass Effect 3, but that's not confirmed one way or the other.
"Arrival" is the last piece of story based content for Mass Effect 2 and the final piece of the bridging DLC mentioned above. Arrival is essentially a side mission, yet it has many implications towards Mass Effect 3. The main story of Arrival sees you discovering the secrets of an imminent Reaper invasion and doing everything you can to stop it. This eventually culminates in the reality of destroying the "Alpha Relay" located in a Batarian system on the edge of the galaxy. The immediate repercussion is the fact that by destroying said relay, you deny the Reapers access to their closest option for intragalactic travel. This act directly sets the stage for their inevitable Arrival in Mass Effect 3.
However, the DLC itself doesn't go too deep into the Reapers' future plans and mainly hits on some of the direct consequences that are to become of Shepard by destroying the Alpha Relay.
Before the Relay is actually destroyed, Shepard's attempt to contact the Normandy is intercepted by none other than Harbinger, the supposed "leader" of the Reapers. The conversation that ensues after this is brief, but meaningful.
Much akin to his speech at the end of Mass Effect 2 itself, Harbinger reiterates the fact you're only delaying the inevitable as the Reapers will always find a way to the Galaxy. We know this to definitely true as you can see the Reapers razing Earth in the Mass Effect 3 debut trailer, which is currently the only info we have on the game. Regardless of the redundancy of Harbinger's speech, it's nice to see some direct interaction between Shepard and the Reapers, especially since Mass Effect 2 did so little to play up the imminence and danger of the Reaper threat. While it turns out to be much ado about nothing, Arrival does a great job of reestablishing the Reapers as the prime threat to the galaxy. In fact, if you let the countdown clock in Arrival expire, you actually see a quick vision of a Reaper invasion.
Truth be told, the real beef of the bridging story in Arrival revolves around that of the Alliance. After the mission is complete, Admiral Hackett personally arrives on the Normandy SR2 to debrief Shepard on the events that took place. While Shepard was successful in stopping the immediate Reaper threat, his or her actions also detonated the Alpha Relay, which had devastating effects.
As the picture above states, almost 305,000 Batarians were wiped out when the Relay was destroyed. Hackett makes it clear that while there is no concrete evidence against Shepard, the Alliance will be looking for a scapegoat to blame to avoid a war with the Batarians. This is the most intriguing bit of info, as it implies that maybe Shepard will be charged with this or some sort of other wrongdoing at the beginning of Mass Effect 3, thus kickstarting the events in one way or another. All we can do now is wait for the info revolving around ME3 to slowly trickle out.
Now that Mass Effect 2 is completely wrapped up, don't forget to keep an eye on our main page for info regarding Mass Effect 3! Also, don't forget to check out our Mass Effect 3 thread on our forums!