In Gotham City Park, Poison Ivy has her female minions capture Batman and bring him before her. When he refuses her offer to rule at her side, Poison Ivy orders her Flower Children to feed him to a hungry carnivorous plant. However, Batman warns the villainess that they'll stop her. His concealed ally, Black Orchid, removes her Flower Child disguise. As she fights off Ivy's minions, the others throw Batman into the plant. Using a hidden grenade, he blows it up and a furious Poison Ivy attacks him. Even with his hands tied behind his back, Batman is the superior fight. Ivy commands giant vines to grab Batman and gives him one last chance to join her. Black Orchid arrives and defeats the villainess, and then slips away.
Catwoman breaks into a museum to steal the two-sided Cloak of Neferteri, a gift from the goddess Bast. Batman arrives to stop her, noting that the Cloak is reputed to give the wearer nine lives. They fight to a draw, but Black Canary and Huntress arrive and find Batman in something resembling a romantic clinch. However, the heroines tell Batman that they're to stop someone else: Two-Face. Black Canary disarms them with her sonic cry, and the heroes take on the henchmen while Catwoman confronts Two-Face. Two-Face, unimpressed, tells her that he plans to put it up for bid and then draws a gun and shoots at her. Another henchman drops a sarcophagus on her and Batman is forced to save her, letting Two-Face escape with the Cloak.
Catwoman offers to help them track her down, and Batman agrees to hear her out. The villainess explains that she knows the location of the underworld summit at the Double Decker Club, and figures that's where Two-Face is holding the auction.
The heroes split up and arrive separately. Black Canary and Huntress arrive first, in their civilian identifies. Catwoman arrives, and Black Canary is angry when she learns they're wearing the same dress. Before they can fight, Batman arrives, disguised as Matches Malone, an underworld snitch. He tells the women to play along as his bodyguards. Catwoman immediately attaches herself to him and they go into the club.
Inside, Two-Face begins the auctions and shows off the Cloak. However, the mobsters double-cross him and prepare to take the Cloak and shoot Two-Face. Batman and the others attack but a stray shot brings a spotlight down on his head. Two-Face knocks out the head mobster and the women come to Batman's aid. However, he snaps at them and then tells Two-Face that they're the Birds of Prey. The women are forced to flee, while Batman tells Two-Face that he's taking the Cloak. When Two-Face's men attack, Batman holds them back long enough to don the Cloak, and then offers them double to work for him. They all agree to work with "Matches."
Matches robs a bank and is gunned down by the police, but the Cloak resurrects him. Subsequently, Matches is drowned and burned in a car crash but emerges unscathed. As he steals from other criminals, Two-Face reads of his exploits with growing fury, and wonders why Batman isn't intervening.
Matches holes up at the Iceberg Lounge, unaware that Catwoman, Black Canary, and Huntress are watching him. They sneak in backstage but find themselves on stage as the curtains open, and find themselves face-to-face with Gotham's underworld. The women pretend to be a singing group and perform. They're a big hit with the crowd but are unable to get through to Batman. Matches orders their deaths and they attack him, but he easily subdues them.
Matches lowers the tied-up heroes into a shark tank but halts it at the last minute and explains that they're merely bait for Batman. When they wonder what happens if Batman doesn't show up, he admits he'll feed them to the sharks anyway. However, the heroines are shocked when Batman arrives and attacks Matches. When "Batman" draws a pair of guns and opens fire, Matches takes cover and a stray bullet hits the shark tank controls. As they're lowered down, Huntress has Catwoman grab her crossbow pistol and get it to her. Once she has it, Huntress fires a ricochet shot and slice open Black Canary's gag. She uses her canary cry to shatter the tank.
Matches realizes that he's not facing the real Batman. "Batman" runs to the roof and Matches gives chase. He pulls off the Caped Crusader's mask and reveals... Two-Face. Two-Face thanks Matches for confirming the Cloak's powers, and shoots the sign above Matches. The women arrive and knock Two-Face out, and Catwoman realizes that Matches is down to his last life.
Matches is resurrected and emerges from the rubble, and goes after them for ruining his plans. He knocks out Black Canary and Huntress, and corners Catwoman on the edge of the roof. She asks for a last request and kisses him, and then kicks him off the roof. He falls over 20 stories to his death, and Huntress and Black Canary demand to know what she's done. Below, Matches comes back to life, and Batman removes his disguise. He then explains that when Matches' last life died, Matches disappeared for good. Catwoman slips away, taking the Cloak with her, and Batman calls it even for now.