Act 1
Mr. Jacob Jankowski, an elderly Polish-American man living in an assisted living home, visits O’Brien’s One-Ring Circus before it heads out of town. He reveals to the employees that he worked with circus animals in his youth. He reminisces on his first circus job. During the Great Depression, Jacob hops a train "going anywhere." Camel, an older circus worker, and Wade, the foreman, try to intimidate him off the train, but he stands his ground. Camel reveals to Jacob that the train belongs to the "Benzini Brothers Most Spectacular Show on Earth" ("Anywhere/Another Train"). Jacob is hired for one day’s work and will leave after their next stop ("The Road Don’t Make You Young").
Jacob walks in on Marlena, the star performer, comforting her horse, Silver Star ("Easy"). Jacob, who studied veterinary medicine at Cornell, shows August, the ringmaster and Marlena’s husband, that the horse is foundering and may need to be euthanized. After hearing that Jacob was studying to be a doctor before being forced to drop out of school, August offers Jacob a job as the circus vet if he is able to keep Silver Star working. August takes Jacob to the menagerie and tricks Jacob into getting attacked by a toothless lion - he boasts that nothing at his circus is real as people only want to see spectacular illusions instead of the grim reality ("The Lion Has Got No Teeth"). Later that night it's revealed that Wade "red-lighted" another circus worker on August’s command, throwing him off the train. Camel warns Jacob of the dangers of the circus, but Jacob decides to stay because he has nowhere else to go ("I Choose the Ride").
Jacob ultimately has to put Silver Star down as the injury has progressed beyond saving. When the circus arrives at the no-longer-in-business Fox Brothers Train, August plans on buying a horse to replace Silver Star. However, all that remains is an old elephant, Rosie ("Ode to an Elephant"). Jacob and Marlena struggle to train Rosie ("Just Our Luck"), and August, unsatisfied with their progress, begins to abuse Rosie with a bullhook. Marlena tells Jacob that August is prone to fits of rage ("I Shouldn’t Be Surprised").
Jacob, Marlena, and August spend the evening at a speakeasy. Jacob tells them that he had been studying to be a doctor to follow in his father's footsteps and his father had even ordered a sign reading "Jankowski and Son" to put over their practice, but he and Jacob's mother were killed in a car accident before he could pass his final exams. Jacob had hopped the train because the bank had confiscated his childhood home as well as his father's practice, so he was leaving the city to start a new life. Marlena empathizes with Jacob's story as she had run away from her family to marry August. Jealous of the tender moment, August becomes violent again, this time towards Marlena. When the speakeasy is raided, Jacob and Marlena escape from the police together. Outside of the speakeasy, they share a moment, and Jacob kisses Marlena. Marlena runs away, and Jacob revels in his thrilling situation ("Silver Stars").
In Chicago, Marlena and Rosie are set to make their debut as the star act, but Rosie refuses to move, forcing August to improvise. Furious, August prepares to beat her with his bullhook when Rosie swipes August down with her trunk. She is about to kill him when Jacob instinctively yells zostań, the Polish word for "stop". Rosie, whose previous trainer was Polish, understands the language and can now follow Jacob’s commands. The circus celebrates finally being "back in business" ("The Grand Spec").
Act 2
Mr. Jankowski reminisces on his younger days spent with Rosie ("Funny Angel"). With Rosie as their new star, The Benzini Brothers Circus becomes a success. As Jacob teaches the circus workers Polish, he grows increasingly close with Marlena ("Zostań"). This draws the eye of circus workers Barbara, Walter, and Camel, who convince Jacob that a relationship with Marlena will bring nothing but trouble ("Squeaky Wheel").
Jacob plans to leave the circus to Marlena’s dismay - August grows suspicious of their relationship. He accuses Marlena of cheating on him and Marlena and August exchange blows ("You’ve Got Nothing (Part 1)"). August orders Wade to red-light Jacob, Walter and Camel. Jacob and Marlena disappear, and a reluctant Wade pushes Walter and Camel off the train as it’s going over a bridge, killing them ("You’ve Got Nothing (Part 2)").
In a hotel room, Marlena regrets how poorly she let people treat her, but resolves to trust herself from now on ("What Do You Do"). Jacob finds Marlena, and they are free to be together for the first time ("Wild"). They form a plan: They will go back to the show, perform the first half, then run off with Rosie, Camel, and Walter while August finishes the show. When they arrive at the circus, Jacob goes to Walter and Camel's compartment, but only finds Walter's pet dog Queenie. Wade walks in on him and Jacob realizes what happened. The two end up fighting until Wade smacks Jacob's head against a post and runs off. When he comes to his senses, Jacob takes a knife and resolves to kill August as he takes a nap before the show ("Go Home"), but can’t go through with it.
During the show, a guilt-ridden Wade opens the menagerie cages, and the animals stampede the circus. Many people die, including August, who is killed by Rosie wielding his bullhook. Jacob and Marlena make it out alive and soon after got married, keeping Rosie and Queenie in their care. Jacob went on to pass his exams and they had five children, allowing Jacob to finally hang the sign his father had ordered before he eventually retired and left the practice in the hands of his children. After revealing that Marlena died not too long ago, Mr. Jankowski decides that he misses the circus life, and accepts a job at O’Brien’s One-Ring Circus, jokingly telling Marlena's spirit that he's running away with the circus before declaring that he's finally home ("Finale (I choose the ride)").
