After an uneven but improved freshman season, Gotham returns on September 21 with the next chapters of good guys James Gordon (Ben McKenzie) and teen Bruce Wayne (David Mazouz) set against the corruption bubbling inside their dank city. But let’s face it, the real fun of the show is that its a showcase for the town’s evolving villainy, many who are en route to becoming iconic DC bad guys like The Joker, Riddler and Penguin. Smartly, the producers embraced that hook and are centering their sophomore season on that host of hooligans in the making. So if you’ve never tasted the dark delicacies of Gotham, or want to jump back in, here’s what you need to know to get back to speed…

Season two’s tagline certainly isn’t being coy about laying out the focus of the yearlong arc. In fact, Arkham Asylum, the holding pen of nefarious criminals, will be front and center in the season premiere introducing some new, or re-focused, schemers to kick off the chicanery.

Det. Gordon had a rough first season learning from rumpled partner Harvey Bullock (Donal Logue) that by-the-book policing has no place in Gotham City. By the season one finale, Gordon helped bring down the powerful Falcone crime boss but now he’s being punished for it by his own department. Season Two promises a disillusioned, demoted Gordon willing to work with the bad guys, like Oswald Cobblepot (Robin Lord Taylor), to make some good happen.

Michael Chiklis, the mighty man behind The Shield’s Vic Mackey, comes back to the badge in Gotham as Gordon’s Captain and the precinct’s resident ball-buster. Producers tease that Barnes will have some major issues as the season progresses with Gordon’s new tactics to achieve “justice,” which means Chiklis will be getting incensed and that’s always good.

The future kingpin Penguin is still making his mark as smarmy Oswald Cobblepot, the underling with visions of grandeur. He weaseled his way into power at the end of Season One with the fall of rivals Falcone and Fish Mooney (Jada Pinkett Smith), but don’t expect his reign to last long. Taylor works best when his Cobblepot is desperate for respect and power so look for several steps back for his character.

Move over Cobblepot, hello suave, diabolical industrialist Theo Galavan, played by the perennially venial James Frain. The ambitious mover and shaker will saunter into Gotham with his sister, Tabitha, looking to wow the citizenry, all the while conscripting the potential agents of chaos residing in Arkham as his minions of treachery. What his ultimate goals are will be a major part of the unfolding arc.

Tabitha Galavan (Jessica Lucas) is Theo’s gorgeous, enforcer sister will help build her brother’s empire of villainy. The siblings share a potent secret vendetta that is at the heart of their plans. Fans of the DC versions of Tigress, beware this is a new take on the super-villain character from the comics.

Young master Wayne lost his parents in the pilot and believed Gordon would solve the case of who murdered them. Gordon fell short, so the young man is taking matters into his own hands this season. With the discovery of his father’s secret cave in the first season’s finale, Bruce will be more proactive in building evidence to crack the case and gaining skills that will move him towards his Batman destiny.

There’s only so much a billionaire teen can do when he hasn’t hit puberty and doesn’t have a license to drive. Enter Bruce’s internal wingmen, manservant Alfred Pennyworth (Sean Pertwee) and Lucius Fox (Chris Chalk), a Wayne Enterprises employee who has key information about Bruce’s father’s secret pursuits. The two men will be key mentors in Bruce’s evolution and become his physical muscle as the season unfolds.

Introduced in season one as a Gotham City PD forensic scientist with a penchant for riddles, Edward Nygma (Cory Michael Smith) worked closely with Gordon and Bullock. On the down low, he murdered the abusive boyfriend of the woman he fancied which kicked off his dark descent. By season’s end, Edward had a mental breakdown, complete with dual personality Riddler talking in his head. He’ll continue to fight his dark impulses this season without much success.

The relationship between Gordon and his now ex-fiancee Barbara Kean (Erin Richards) took a nosedive as Barbara went full bad girl by the end of season one. She was trucked off to Arkham Asylum where she’s going to meet a rogue’s gallery of kindred spirits including Theo and ginger troublemaker, Jerome Valeska (Cameron Monaghan). Rumors abound that Kean’s end game may be as the Joker’s partner in crime Harley Quinn, so keep and eye out for signs.

Briefly introduced in season one as a circus worker who murdered his sexually deviant mother, Jerome was arrested and thrown in Arkham Asylum where we find him in season two. His bold, outlandish personality catches the attention of both Barbara and Theo. Producers won’t confirm that Valeska is indeed the Joker in Training but everything from his red hair, freaky wide-mouthed smile and chaos-fetish is screaming that he is.

Tara Bennett is a pop culture writer, author of Showrunners: The Art of Running a TV Show and the The Sons of Anarchy Official Collector’s Edition. She might be overly enthusiastic about xenomorphs and otters. Follow her at @taradbennett.