The Mockingbird

Late one night in the mansion of the Secret Six, Catman and Deadshot have a discussion about their unknown leader, Mockingbird, and about the dramatic change in Catman's life, while Cheshire secretly listens in the shadows. Afterwards, Scandal informs everyone that Mockingbird has just assigned them to steal Thanagarian weaponry from a tanker in Gotham harbor.

Upon their arrival at the tanker, the Six are ambushed and captured by members of the Society, including Weather Wizard, Cheetah, Doctor Polaris, Count Vertigo, Killer Frost, Captain Nazi, Hyena, Crazy Quilt, and others. The Crime Doctor tortures the Six, asking them, among other questions, the identity of Mockingbird. After a few rounds of torture, Catman breaks free and rescues his teammates. While escaping, the Six decide to send the Society a message. They murder one of the two Hyenas.

The Six then infiltrate a Society installation in Brazil. After fighting their way through a legion of H.I.V.E. troopers, apparently led by the Queen Bee, they discover the Society's plans for the "Vindication Scenario": erasing the memories of all of Earth's superheroes. The facility is a giant battery, powered by kidnapped heroes Firestorm and Gehenna. The Six release Firestorm just as Black Adam arrives with a response team, and the facility is destroyed.

Betrayal

Once the Six return to their base, Cheshire and Catman are in bed together when Cheshire accuses Catman of being a spy and wanting to be a hero. However, she reveals that she has slept with him in order to conceive a child.

A short time later, most of the Society's founding council votes to mount a final strike on the Secret Six — Lex Luthor disagrees with a preemptive attack, but the remaining four members (Black Adam is absent for unknown reasons) decide the action is necessary. Simultaneously, the Six agree to a last stand, but only under the condition that any survivors be set free from Mockingbird's control with no strings attached.

The Six hunted

Prior to the battle between the Society and the Six, Deadshot visits Scandal's room to talk about the team's future. A framed picture on the woman's desk reveals that her father is the immortal Vandal Savage. Before the conversation can progress past basic greetings, Catman ambushes Deadshot and admits knowing that he (Deadshot) masqueraded as the villainous Deathstroke and murdered the lions in his pride. The two scuffle before finding the real Deathstroke leading a small band of villains to the front door of the House of Secrets.

As the crew debates how the Society found them, Cheshire confesses to several traitorous deeds, including giving Luthor the coordinates of the Six's base and covertly joining the Society. When asked why she would do such a thing, considering Mockingbird's threat to kill her daughter if she does not comply, Cheshire points out that the baby she is having with Catman would make a fine replacement for a lost child.

Mockingbird revealed

The Society storms through the castle, and Cheshire is shot by Deathstroke, who comments that "The Society doesn't need traitors". The Secret Six, however, fights back successfully. Talia and Scandal, daughters of immortals Ra's al Ghul and Vandal Savage, respectively, fight each other. Just when Talia has the upper hand, Scandal's mole in the Society, Knockout, knocks her out (it is also revealed that Knockout is Scandal's lover). Ragdoll convinces Solomon Grundy, a fellow "ugly monster", to switch sides. Ragdoll fights his father until Parademon beats the elder Rag Doll. Catman and Ragdoll Jr. escape from Black Adam's group while Parademon blows up himself, Rag Doll and the battleground. Deathstroke and Deadshot duel, ultimately shooting each other at the same time. To save his daughter Scandal, Vandal Savage infiltrates the Society's headquarters and threatens to kill Luthor if he does not disengage the attack against the Six. Reluctantly, and over Black Adam's objections, Luthor ends the battle. Deadshot is led to medical help by the surviving members of the Secret Six.

The central revelation of the book is that Mockingbird is actually Lex Luthor and that the Luthor who organized the Secret Society is an "imposter" (in reality, Alexander Luthor, Jr.). Mockingbird/Luthor reveals that he chose those six individuals because each had different knowledge and experience that could be used to oppose the Society: Catman, for his knowledge of Batman's villains; Deadshot, for his knowledge of the remaining Suicide Squad members; Parademon, for his experience living on Apokolips; Ragdoll, because he grew up as a "nephew" to the members of the Injustice Society; Scandal, because she grew up with Vandal Savage and his associates; and Cheshire, for her knowledge of the Teen Titans villains. Mockingbird/Luthor reveals to Scandal that he never placed the families of the Six in danger and disbands the team. Also notable is the Society Luthor's apparent murder of Pariah, a character from the original Crisis.