If you asked film critics what Hollywood trends they most loathe, two of the most popular answers would be "sequels" and "origin stories." Too often studios rush to cash-in on the fandemonium of a could-be film franchise by making follow-ups that miss out on the spirit of the original, misunderstand what fans loved about the characters, or just don’t make much sense at all. Yet in a sea of summer sequels, Disney and Pixar have doubled down, plunging once more into the aquatic world of "Finding Nemo" with "Finding Dory," which not only retraces the cross-the-ocean antics of the first film, but also dives back into the origins of its breakout scene-stealer. And yet, it's terrific!

Returning co-writer/director Andrew Stanton ("Finding Nemo") knows what audiences loved about the original, and delivers with sumptuous animation, quirky characters, goofy humor, and loads of heart. "Finding Dory" gives us plenty of time with our favorite forgetful fish (Ellen DeGeneres), rolling back to how she ran into Marlin, why she was all alone, and where her chipper mantra "Just keep swimming" came from. But unlike most of the origin stories Hollywood's been dumping out of late, this one actually enhances the character, giving a context to Dory's signature spins from hopeful to panicked. However, parents be warned: this journey is both heart-warming and heart-wrenching.

The heart-warming bits begin with an itty-bitty baby Dory (Sloane Murray) bobbing about, playing with her parents (voiced warmly by Eugene Levy and Diane Keaton). Loving but concerned, her parents teach Dory songs and games they hope will keep her close to home and thereby safe. The short-term memory loss that was played for laughs and pathos in the first film takes on a grander meaning here, becoming an allegory for special needs. Her parents' fears are realized when Dory is swept away from them by a merciless undertow. Lost among strangers, Dory doesn't know how to communicate the help she needs. So, alone, she just keeps swimming.

Of course, we know Dory does find friends and a family with Marlin and Nemo (Albert Brooks and Hayden Rolence). But when a fleeting memory of her folks drives Dory to charge off into the open ocean once more to find them. All too familiar with the pain of such a separation, Marlin reluctantly goes along with his son Nemo in tow. Guided once more by the snippets of Dory's memories, they ride turtles across the currents, and wind up at a marine institute, where they meet a colorful cast of creatures, including a nearly blind whale shark (Kaitlin Olson), a neurotic beluga (Ty Burrell), a pair of cockney-accented sea lions (Idris Elba and Dominic West in the weirdest, most playful reunion from "The Wire" ever), and a cantankerous octopus with a heart of gold named Hank (Ed O'Neill).

"Finding Dory" tosses its quick-finned trio across sea, air and even land in an increasingly outlandish and out-of-the-box (or tank) adventure, peppered with visual gags like a wall-eyed loon named Becky and an unexpectedly charming running joke about sea animals inherently trusting Sigourney Weaver -- not a character voiced by Weaver, but the "Alien" actress herself! On top of all this, the voice work here is fantastic, full of vibrancy and character. DeGeneres so deftly spins from guileless joy to anxious alarm that Dory wiggles into your heart and makes it her helpless plaything. Yet it's O'Neill's grump octopus who is the franchise's new scene-stealer. With the ability to camouflage himself to the point of total invisibility, and his lovable grumbling at Dory's moxie, Hank proves a spectacular foil to the titular fish. And Pixar knows it, piling on Hank-centric visual gags all the way through the credits. (Also, be sure to stay through the credits for a special bonus scene!) All this makes for a wonderful time to be had by the whole family, though parents with skittish children my want to avert their eyes during the creepy giant squid section!

Yet what really makes "Finding Dory" a standout is its message. Dory is different from the sea creatures around her. But "Finding Dory" argues that different is not bad, as Dory herself worries it is. Influenced in part by her parents concerns, Dory fears that her special needs will isolate her from others, fating her to a terrible loneliness. In one heart-wrenching moment early on the wee fish asks he parents, "What if I forget you? Will you forget me?" Of course they won't. Neither will any of the other sea creatures whose lives Dory's optimism and courage has touched.

In this journey, Dory faces her fears and discovers her own special abilities, how they unite those around her, how they inspire her friends to attempt the seemingly impossible, and how they allow her to achieve the incredible. Dory's disability does not define her. It's a part of what makes her who she is, and who she is is wonderful.

On the surface, "Finding Dory" is a fun-filled emotional rollercoaster ride, sure to make kids cheer and parents tear up. But beyond that, it's a movie that will likely mean the world to those living with special needs, or those who love them. Pixar has given them a hero who is special and needed.

"Finding Dory" opens June 17^th.