“Long ago,” Kung Fu Panda 2 begins, a young peacock found himself rejected by his royal parents. This backstory for Lord Shen (Gary Oldman) appears in animation that resembles paper puppets, at once delicate, traditional, and colorful. The narrator (a soothsaying goat voiced by Michelle Yeoh) reveals Shen’s plan for vengeance: he means to convert fireworks—a technology intended to “bring color and brightness”—into a weapon that will instead “bring darkness.”

Alas, you may think as you sit in a theater wearing 3D glasses, the seer might as well be describing this technology too, as movies once colorful and bright are now delivered into darkness.

That’s not to say that this film is all dark, at least thematically. In fact, Shen’s grim story has a parallel, that of Po (Jack Black), the roly-poly kung fu champion. It turns out that he too was long ago abandoned by his parents—though not because he was a child who deserved to be rejected, like the Lord Voldemort-ish Shen. Instead, Po’s parents were trying to save their adorable bundle of fur and fat, as Shen was, for his part, trying to kill off all pandas, because the goat had prophesied that such a bear would eventually defeat Shen. And so, though neither Po nor Shen knows it, their life paths are intertwined.

You do know, however. You also know, if you’ve seen the first film, that Po has never before given much thought to his background, assuming that his dad, the big-hearted goose Mr. Ping (James Hong). Po starts to wonder though, when he has flashbacks of the moment when his mother left him in a radish basket, the horror rendered in a chaotic tilts and shadows, and then, most emphatically, in a poignant point of view shot: the baby panda’s paws are outstretched toward her tearful face as he whimpers.

Shaken by the vision, Po takes a break from training with the Yoda-like Master Shifu (Dustin Hoffman) and the Furious Five—Tigress (Angelina Jolie), Monkey (Jackie Chan), Mantis (Seth Rogen), Viper (Lucy Liu), and Crane (David Cross)—in order to ask Mr. Ping a rather existential question, namely, “Where did I come from?” Mr. Ping, however, has no answers. All he knows is that the cute baby bear arrived on his doorstep in the radish basket, and that he had a tremendous appetite.

As Po ponders his past, Shen is busy planning for the future. He directs a veritable army of laborers—miserable wolves, led by the one-eyed Wolf Boss (Danny McBride), who dismisses Po as “big and furry, soft and squishy, kind of push and cuddly”—to construct his “unstoppable” weapon, working in a dark cave, filled with smelter fires and smoke. At the same time, Po and his fellow warriors are journeying to Shen’s palace for a confrontation, and so replicating the basic plot of the first film. This even as Po worries out loud that it might be hard to use kung fu to stop a weapon that is intended to stop kung fu.

Po regains his mettle when he meets a couple of his idols, the kung fu warriors Master Storming Ox (Dennis Haysbert) and Master Croc (Jean-Claude Van Damme). They’ve witnessed the effects of the weapon, and suffered from its darkness, and so they’ve decided to stay imprisoned in the grim cell where Shen has parked them, instead of fighting back. They shudder and grimace, remembering the horror and destruction.

Po and his buddies, lacking both that memory and a sense of their own vulnerability, press ahead. But the sequence in the prison suggests how war works, how devastation and abuse breed not only revenge and resentment (a la Shen) but also fear and exhaustion (as in victims). The film’s familiar point is that heroes like Po save the day, but this glimpse of systemic oppression is just a little daunting.

Lucky for everyone, Po is as determined to do kung fu as he is to eat dumplings and cakes. And so he pursues the state that Master Shifu has called “inner peace,” a balance of his past and present, his nightmares and his dreams. And so he finds it, by way of a tremendous showdown, with explosions and fires and all manner of havoc wreaked.