The original adventure-comedy follows Op and Ed, two adorable donut-shaped animals -- FLUMMELS -- who accidentally time-travel from 1835 to modern-day Shanghai.  There they discover traffic, trans fats, and worst of all, that flummels are now extinct. It's up to this bumbling pair to save themselves and their species... and, just maybe, change the course of history.

OP (Rachel Bloom) and ED (Adam Devine) are sister and brother flummels - cute, furry donut-shaped animals who live on an island in the Galapagos in 1835. Ed, a grumpy pessimist, desperately wants to fit in with the community while Op, overly exuberant, constantly creates havoc that makes them outsiders.  When Op’s impulsive actions end up ruining the preparations for the upcoming Flower Festival, Op and Ed are banished. Undeterred, Op leads Ed up the far side of the mountain to the forbidden zone in search of flowers so wonderful the flummels will have to let them rejoin the festival.  There, to Op and Ed’s amazement, they discover a large, mysterious glowing flower which opens up and, with a magical pulse, sucks both Op and Ed into it. They plummet through a colorful time portal and pop out into a house in… modern day Shanghai.

In Shanghai, Op and Ed meet CLARANCE (Ken Jeong), an adorable little dog. Clarance tries to help them understand where and when they are, and decides he will help them get back. He takes them to a museum where they learn, to their horror, flummels went extinct in 1835 – right after they fell into the time flower. Op and Ed realize they have to return to 1835 and save their species.

Clarance offers Op and Ed another “time flower” that his scientist owner, the dearly departed Dr. Chung, has been experimenting with. This transports the trio to a place that exists outside of space and time – Dr. Chung’s amazing Time Terminal. There, hundreds of time flowers connect, each leading to different points in history. Unfortunately, another Op and Ed accident throws Clarance into a random portal and the little dog is lost in an unknown time and place.

Unsure what to do, Op and Ed meet “THE EXTINCTABLES” - a family of odd, extinct creatures who live for all of eternity in the safety of the Time Terminal. With their help, Op and Ed must first search for Clarance in order to find their way back to save the flummels. Even as brother and sister squabble, they’re able to find Clarance in 1917’s Antarctica, chained to Ernest Shackleton’s team of sled dogs. They all manage to get back to the safety of the Time Terminal safely, but not without the triceratops Extinctable getting wounded.

Op’s impetuousness almost got the last dinosaur killed! Ed is furious with his sister and they have a huge falling out. Realizing she’s at fault, Op sadly sets out on her own to return to her 1835 Galapagos home and warn the other flummels about their imminent extinction.

In the Galapagos, Op tries to convince the flummels about everything that she’s been through. She’s discovered they are all in danger from the island volcano that is about to swallow them. But there’s a surprise for Op, Ed and the others when they learn the true reason flummels went extinct. All hope seems lost as our tiny flummel heroes must try to save their entire species all by themselves. The odds seem insurmountable until the Extinctables show up to help save the day. Okay, the odds are still insurmountable as the Extinctables will now be destroyed alongside Op, Ed and the rest of the flummels. In the end we can only hope that Op and Ed become heroes and flummels will go on to live among us today.