After the destruction of the Citadel (ending of Mass Effect: 1 video game), Commander Shepard's ship (the Normandy) is attacked and his body is taken. It's been a month or so since that attack and Dr. Liara T'Soni has found a contact with information on Shepard's body. Liara was a teammate and possible romantic interest from video game based on in-game RP decisions.
For the Mass Effect fans, like me, the issue starts off with a little recap of what's happened since the end of the video game and provides a familiar face (Liara). The lovable Elcor <sarcastic> are back with their strange way of speaking their inflections and emotions, which is explained to the new fans after the Elcor is finished talking by a new character of a new race that wasn't seen in ME1. Feron, a Drell, is introduced as someone with information on Shepard's body. In ME2, one of your teammates (Thane) will be a Drell biotic, so it's nice to get introduced to someone from that race before the game arrives.
The book brings back the Cerberus group, Illusive Man, Shadow Broker, and the Collectors - each from either the video game or the Mass Effect novels. There's also the usual bunch of Turians and Krogan along with Batarians (introduced in ME:1 add-on).
Omar Francia and Michael Atiyeh used the "feel" of Mass Effect through out the book. As in the game, there's lots of blues and reds and round objects. Mac Walters, the lead Bioware writer for ME:2, writes a good story and I end the book wishing there was more to read.
I've read both Mass Effect novels and finished the video game a few times completing nearly every quest, so I'm quite familiar with the sci-fi setting. For a new fan, some things are left unexplained such as what powers a biotic has and what role Liara had in Shepard's life. The races are not introduced and there is little explanation (other than the inside cover) to the relationship between humanity (the humans) and other races. If you're a new fan and haven't read the novels or played the first video game, then I recommend you pick up both novels and read them! :)
The video game will be released on Jan 26, 2010 and all pre-orders will also contain a copy of this issue.