After the second season of "Gotham" kicked off on Sept. 21 with "Damned If You Do," the hard-hitting second episode, "Knock, Knock," appeared on the small screen on Monday, as James Gordon (Ben McKenzie) was reinstated to detective in a deal with Oswald Cobblepot (Robin Lord Taylor).

Directed by Rob Bailey, the second episode of the series was a thrilling follow-up to the first. While Gordon reaped the benefits of Cobblepot's favor, Barbara Kean (Erin Richards), Amygdala (Stink Fisher), Jerome Valeska (Cameron Monaghan), Richard Sionis (Tod Stashwick) and others were broken out of jail by newcomer and mastermind Theo Galavan (James Frain) and his sister Tabitha Galavan (Jessica Lucas).

"Knock, Knock" revealed that Jerome and the rest of the Arkham inmates, dubbed "the Maniax," weren't looking to waste any time causing mayhem. The criminals kidnapped seven shipyard workers and forced them off the roof of the Gotham Gazette. They tagged each hostage with a spray-painted letter, before tossing them off the roof, spelling the word "Maniax."

Meanwhile, young Bruce Wayne (David Mazouz) and Alfred (Sean Pertwee) explored the secret office tucked behind the fireplace. Bruce, who's eager to learn more about the life of his father, sought to explore his father's computer, but Alfred smashed the hard drive with a hammer, hoping to protect Bruce. In a fit of rage, Bruce then fired Alfred.

Spoiler: The two make up because they're fond of one another. Also, Alfred agrees to train Bruce, lets him carry out his father's work and fixes the computer.

Also, Jerome became the leader of the Maniax just as Gordon was assigned to the case. A tip from Gordon's former partner Harvey Bullock (Donal Logue) took him to the shipyard, where he learned the Maniax gang stole a refueling truck.

The team of villains chose to display their lack of sanity by hijacking a school bus filled with cheerleaders, then attempted to set them on fire. Luckily, that plan failed. Jerome managed to escape while another man tried to finish the job. Gordon managed to disarm him, but Tabitha shot the man with a sniper rifle just in case he decided to talk.

After Gordon returned to GCPD headquarters, Barbara called to tell him that she wanted to turn herself in. However, her appearance at the station was simply to lure Gordon away while Jerome and his pals from the asylum arrived to shoot every cop in sight.

When Gordon was some distance from the precinct, he was nearly beaten to death by a member of the Maniax, but Barbara interrupted the assault. She insisted that Gordon return to the station because he didn't know what had happened while he was away. By the time Gordon returned, he found that Police Commissioner Sarah Essen (Zabryna Guevara) had received fatal wounds. The loss provoked Bullock out of retirement and back onto the force.

During the attack on the headquarters, Dr. Leslie Thompkins (Morena Baccarin) managed to hide, and Nygma (Cory Michael Smith) momentarily defeated his inner demons to save Kristen Kringle (Chelsea Spack).

During the upcoming episode of "Gotham," "The Last Laugh," Gordon and Jerome will engage in a major standoff. Also, Gordon and Bullock will track down a nemesis from the past.

Episode 3 is scheduled to air Monday night, Oct. 5 at 7 p.m. ET on Fox.