Dark Horse is releasing the digital versions of the Mass Effect comics for free today. This offer is only available for a limited time, and includes all four issues of Redemption and Evolution.
The first comic, Redemption, follows Liara T'Soni leading up to the events of Mass Effect 2, as she deals with the Shadow Broker and protects the interests of Commander Shepard. Evolution concerns itself with the background of the Cerberus organization, which includes the origin story of the Illusive Man.
Those intending to read the comic will have to sign up for a free Dark Horse account to view the content. Unfortunately, the content is only available through a web browser and can't be viewed offline, so you'll have to stick it in your browser if you want to read it.
Have at it here.