Ace in the Hole

"Ace in the Hole" is the twenty-sixth and final episode of the second season of Batman Beyond. It shows the origin of Bruce Wayne's faithful dog Ace.

Plot
Terry drives Bruce to a doctor's appointment, and takes Ace for a walk while he is waiting. Suddenly, Ace catches sight of a strange man and becomes wild, chasing after the man, who runs, and dragging Terry along. Terry is unable to stop him, and Ace rips off his leash and disappears.

Bruce confronts Terry, who is baffled as to why Ace chased after the man. Based on his description, Bruce makes a composite drawing of the man's face, and matches it against criminal records. He soon comes up with a match: Ronny Boxer, who has been arrested before on suspicions of animal cruelty and illegal gambling — he is a promoter of illegal dog fights. Both Bruce and Terry are deeply disgusted.

Bruce reports Ace missing to the police and the animal control authorities. Terry wonders that he's not more worried, but Bruce says of Ace, "he's a survivor." Terry reveals that he's got his own scheme for finding Ronny. He's picked up the names of some thugs associated with dog fights, and plans to approach one posing as a kid with a vicious dog he wants to sell (for verisimilitude, he wraps a bandage around his arm — "he did that, and he likes me").

While Terry goes off, Bruce looks at Ace's bone and dish and wonders aloud, "what did they do to you, boy?"

In flashback, Ace's story is told. As a puppy he was sold to Boxer illegally by a corrupt pound attendant, Ozzie. When Ozzie said frankly that Ace didn't look up to fighting, Boxer smiled and said he would make him a champ.

Ace was raised to maturity in Boxer's captivity, deprived and tormented to make him as vicious as possible. In his first fight, he was being matched against a much larger beast, which Boxer honestly didn't expect him to survive. However, just before the fight began, the police raided the arena, and arrested Boxer and his. Ace escaped and lived as a stray for a long time.

One snowy night, while Bruce was making his regular pilgrimage to Crime Alley (the scene of his parents' murder), he was accosted by a Joker, looking to mug him. Bruce beat him away, and told him to be gone. But as he turned his back, the Joker lunged at him. Ace appeared and pounced on the Joker, who tried to beat him off. Angered, Bruce gave the Joker another thrashing, and sent him packing. Seeing that Ace had been hurt, Bruce carried him back to his car.

In the present, Terry's sting has led him to Ronny's hideout, which is empty when he enters it as Batman. He sees what looks like a chemistry lab, and large containers of Cerestone — the growth hormone. Terry is even more revolted.

Ace wanders the streets for a while, but is captured by animal control. Unfortunately he is seen by Boxer's corrupt attendant, who is impressed by his size and strength. He removes Ace's tags, and passes him off as a homeless stray, before selling him to Ronny for a high price.

At first, Ronny doesn't recognize his old fighter. But when Ace growls viciously at him, Ronny puts the pieces together and laughs, saying they must be meant for each other.

Terry tracks down Ronny's latest illegal arena, carved out of the belly of a cargo ship. But Ronny sees him coming and lays a trap. As soon as Terry enters the arena, Ronny seals the doors and introduces him to an early, failed experiment: an unrecognizable beast that may once have been a dog, but is now deformed, vicious, and the size of a bull elephant.

Terry tries to calm the beast, but it is rabid. As he evades its attacks, an impact against the walls of the arena loosens the locks on Ace's nearby cage. Terry manages to hogtie the beast and Ronny decides to shoot Terry with a gun. Ace manages to break free and tackles Ronny, then chases after him as he runs in panic to the ship's stern. The beast manages to snap it's bonds and badly damages Terry's suit. Ace returns and jumps down through a cut hole in the arena's ceiling, biting at the beast just as it has swallowed Terry whole. In shock, it regurgitates Terry, who takes advantage of the beast's distraction to hook a grappling rope around it and attach the other end to his suit's belt, electrocuting the beast.

When Terry emerges from the arena, he follows Ace to the ship's stern, where Ronny is dangling off a rail above the churning propellers, yelling for help.

Terry and Ace return to Wayne Manor, where Ace runs gleefully into his master's arms.

The growth hormone Cerestone was the agent that transformed small-time crook Charlie Bigelow into the villain Big Time, in "Big Time."