As their quest to track down Sinestro Corps rings continues, the Green Lantern Corps discover to their horror that fellow Lanterns Sodam and Arisia have been captured by Mongul and subjected to the dreaded Black Mercy, causing their deadliest fears to be dragged into the light.
⇖ The remaining group of Green Lantern—including Guy Gardner, Kyle Rayner, Bzzd, Stel and Sorak Natu—follow the signatures of their missing comrades. The search leads the Green Lanterns to a planet that is full of dead body parts. The Lanterns continue onward into the planet's atmosphere as they try to avoid hitting anymore body parts than they can possibly help.
⇖ When the Lanterns finally enter the planet, they discover plants that Kyle and Guy recognize as Black Mercy, and when you deal with Black Mercy, Mongul must be nearby.
⇖ Isamot says he's heard a bit on Mongul but nothing of the plant called Black Mercy. Guy and Kyle use their rings to give the rest of the Lanterns a refresher course on Mongul. With the lesson over, there is a bit of discussion about the the definition of justice and when it's appropriate to take a life. The conversation is interrupted by Kyle and Guy who tell the rest of the Lanterns that they need to deal with Mongul and rescue their fellow Lanterns
⇖ Meanwhile, we see Kilowog and Salaak observing the Guardians construct more and more sciencells for yellow power rings. Salaak says that he will be happy when each and every ring is finally under their control to which Kilowog disagrees. He doesn't like having the rings here and if it was up to him, he would have them destroyed, but he's not allowed to finish his sentence as Salaak tells him it's not up to him so there is no need to continue the conversation. Kilowog leaves and tells Salaak to give Voz his regards.
⇖ Inside the sciencell, Voz is listening to one of the Sinestro Corps members as she tells him that her cell will not hold them for long and threatens Vox's family and friends from his sector of 571. Vox replies that he's free to do whatever he wants and she is not and that is the way it will remain forever. Vox than sees that Salaak has brought Vox severed arms to guard and he tells Vox that these severed parts with the rings must be guarded as closely as the terrorists within these cells must be. We see Sinestro biting off skin on his finger as he uses his blood to design something on his cell window. We see other Corps members doing the same thing as Sinestro, we see that they are all making the symbol for the Red Lantern Corps.
⇖ Elsewhere, we see what the Black Mercy is doing to both Sodam Yat and Arisia. With Sodam, he fears that he will be forgotten. He pleads that he has too much left to prove and too much left to lose. He sees death in the form of a rainbow. He pleads that he doesn't want to be the last. Arisia on the other hand is waiting for someone to save her. She finally has her life back and she doesn't want to die. She remembers dying and how it sucked and she doesn't want to be pulled back into the darkness.
⇖ Mongul taunts the Green Lanterns under his control. He tells them how fear is control and when you have someone's deepest fears at their fingertips, they become mere puppets on a string. His underling, Duel Eknham, says he hates this place. His other head says that they could tear apart these two perfectly killable Green Lanterns. The two heads talk about how great it would be to dismember them until Mongul stops them. Mongul then uses the power of the yellow ring to reverse engineer the Black Mercy seeds and shoots them into space to instill great fear.
⇖ The group of Lanterns are hacking the Black Mercy plants when Bzzd informs the other Lanterns that he sees several yellow lights heading into deep space. The Lanterns follow the yellow light to find a bunch of really big Black Mercy plants with Arisia and Sodam Yat inside. When Sorak Natu tries to get their status, her ring tells her that they are slowly being digested by the plant. The Lanterns begin to destroy the plants which they eventually do. Sorak Natu begins to try and work on getting the Black Mercy plants off Sodam Yat and Arisia when it looks like the Lanterns seem to fall out of the frying pan and into the fire. Green Lantern Corps, meet Mother Mercy.