There have been two major story arcs in this book since Rebirth was launched last Spring and each one used a Colored Larntern Corp as their main antagonist. The Yellow (fear) Lantern's of Sinestro kick started the book with an amazing tale of Hal Jordan's return from exile and that was followed up by an Orange (greed) Lantern series where every beloved Green Lantern from Jordan to Rayner, was showcased in each issue.
This arc appears to be using the Blue Lanterns that are fueled by the emotion, Hope.
We pick up from the previous story arc, which can be found in our achieves. On Mogo, the Green Lanterns base, John Stewart and Soranik address the rest of the Green Lantern and Yellow Lanterns that teamed up to defeat the Orange Lantern, Larfleez. The plan is for the Greens and Yellows to join forces instead of fighting each other and any Yellow Lantern found that does not comply will be sent to the sciencells.
Meanwhile Hal Jordan and Kyle Rayner are sent off by the Gaurdians to a hellish planet to find a Blue Lantern of Hope.......