Infinity Train is an American animated television series created by Owen Dennis for Cartoon Network. The series is set on a gigantic, mysterious and seemingly endless train traveling through a barren landscape, whose cars contain a variety of bizarre, fantastical, and impossible environments. Passengers on the train proceed from car to car by completing challenges which help them resolve their psychological trauma and emotional issues. Every season of Infinity Train (referred to as a "Book", each with its own separate subtitle) follows its own storyline and set of characters, although some characters appear across multiple seasons.
The pilot for the series was released by Cartoon Network on November 1, 2016, before being picked-up for a full miniseries due to positive reception, which premiered on Cartoon Network on August 5, 2019. After the conclusion of the first season, Cartoon Network announced that the series would continue as an anthology series. The second season debuted on Cartoon Network on January 6, 2020. The third season began airing on HBO Max on August 13, 2020, with ten episodes airing across three weeks, and the fourth season was released in its entirety on April 15, 2021.
All four seasons of Infinity Train have received critical acclaim for their complex themes and characters, writing, uniqueness, visual animation style, and voice acting. In August 2020, Dennis stated that, although he wanted to continue the series for a total of eight seasons, most of the crew had been laid off and the series was at risk of not being renewed for a fifth season; Dennis suggested that HBO Max might be concerned that the series' stories and themes were too dark and unappealing to children. Promotional material for the fourth season refers to it as the final season of Infinity Train. In August 2022, the series was removed from HBO Max; in October 2023, the show was removed from digital purchase platforms.
Synopsis The series is set on a seemingly infinite train traveling through a barren landscape; the cars of the train contain a variety of bizarre and fantastical environments. The passengers on the train are people it picks up who have unresolved emotional issues or trauma. As they travel through the train's cars, their adventures within give them the opportunity to confront and resolve their emotional problems, represented by a glowing number on their hand that goes down as they successfully confront these issues. Once they resolve their issues and their number reaches zero, a portal opens and they are able to leave the train and return home.
The first season focuses on Tulip Olsen, a girl struggling with her parents’ recent divorce. She is accompanied by a small, confused robot named "One-One", and Atticus, the ruler of a kingdom of talking corgis. She eventually uncovers many of the train's secrets and confronts Amelia, a passenger who, instead of resolving her trauma from her husband's death, has usurped the role of Conductor from One-One and tried to take control of the train. Before leaving the train, Tulip persuades Amelia to try to adapt to the changes in her life.
In one first-season episode, Tulip frees her own reflection from the mirror world and the two part ways. The second season focuses on the emancipated Mirror Tulip ("MT"), now on the run from enforcers attempting to execute her as punishment for abandoning her role as Tulip's reflection. She teams up with Jesse, a new train passenger, as well as Alan Dracula, a silent deer with a variety of powers. She helps Jesse leave the train by helping him learn to stand up for himself, and he returns to the train to help her escape to the outside world as well.
The third season centers on Grace and Simon, the leaders of a cult of rogue passengers, known as 'The Apex', who vandalize the train and assault its denizens to keep their numbers high, believing that the true purpose of the train is to stay as long as possible as a reward. Their travels with a young girl named Hazel and her gorilla friend, Tuba, make Grace more sympathetic to the train's denizens. After Simon kills Tuba, it is revealed that Hazel herself is one of Amelia's creations, and Grace realizes what she thought she knew about the train is wrong. After fighting off Simon's attempt to usurp control, Grace begins facing up to and mending her mistakes.
Set decades earlier, during the period while Amelia is establishing control over the train, the fourth and final season centers on Ryan and Min-Gi, two childhood best friends who want to become famous musicians. Their relationship is strained due to Ryan's brashness and Min-Gi's fear of the future. While on the train, they meet a talking service bell named Kez who has trouble owning up to her mistakes. Ryan and Min-Gi come to realize that they need each other in order for them to move forward in life, while Kez finally apologizes to the train denizens she harmed.
Episodes
Characters Overview Character Voiced by Seasons Book 1 Book 2 Book 3 Book 4 Main characters Tulip Olsen Ashley Johnson colspan="2" Lake / "MT" (Mirror Tulip) Pictured One-One / One Glad-One Jeremy Crutchley rowspan="2" rowspan="2" rowspan="2" Sad-One Owen Dennis Atticus Ernie Hudson colspan="2" Jesse Cosay Robbie Daymond Alan Dracula Silent character Grace Monroe Kirby Howell-Baptiste rowspan="2" Simon Laurent Kyle McCarley Hazel Isabella Abiera colspan="2" Tuba Diane Delano colspan="2" Min-Gi Park Johnny Young colspan="3" Ryan Akagi Sekai Murashige colspan="3" Kez Minty Lewis colspan="3" Recurring characters The Cat / Samantha Kate Mulgrew Randall Rhys Darby colspan="2" Amelia Hughes Lena Headey colspan="2" The Steward Ashley Johnson colspan="2" Ghoms Dee Bradley Baker Megan Olsen Audrey Wasilewski colspan="3" Andy Olsen Mark Fite colspan="3" Mikayla Reagan Gomez-Preston colspan="3" Reflection Police Agent Mace Ben Mendelsohn rowspan="2" rowspan="2" rowspan="2" colspan="2" Agent Sieve Bradley Whitford Toad / Terrence Owen Dennis colspan="2" Nate Cosay Justin Felbinger colspan="2" Lucy Jenna Davis Todd Antonio Raul Corbo Frank Owen Dennis colspan="2" One Jeremy Crutchley Parka Denizens One Kari Wahlgren rowspan="3" colspan="3" rowspan="3" Two Three Keith Ferguson Judge Morpho Margo Martindale colspan="3" Cow Creamer Audrey Wasilewski colspan="3" Pig Baby/Toddler J. K. Simmons colspan="3" Nigel Silent character colspan="3" Morgan Margaret Cho colspan="3"
Main Book 1 – The Perennial Child Tulip Olsen (Ashley Johnson) is a 13-year-old girl struggling with her parents' divorce who finds herself trapped on the train when trying to get to a game-design camp. She is analytical, down-to-earth, and determined to get off the train. Naomi Hansen and Lily Sanfelippo voice younger versions of Tulip, respectively at age 5 and from age 6 to 8. One-One is a spherical robot consisting of two separate hemisphere-shaped robots, formerly collectively known simply as One. In Book 1, One-One accompanies Tulip on her journey, and eventually learns that it is the rightful Conductor of the train. At the end of Book 1, One-One resumes its duties as Conductor, overseeing the operations of the train and passengers. Throughout the background of Book 4, set in 1986, One bonds with Amelia, loosening restrictions on the passengers, before she usurps his position as the Conductor. Glad-One (Jeremy Crutchley) is the exuberant and optimistic part of One-One. Sad-One (Owen Dennis) is the morose and pessimistic part of One-One. Atticus (Ernie Hudson) is a talking Corgi and the king of Corginia, one of the train cars. He accompanies Tulip on her journey. Guest voices for Book One include Matthew Rhys and Ron Funches.
Book 2 – Cracked Reflection "MT" (Ashley Johnson) is Tulip's reflection, freed from the mirror world by Tulip in episode 7 of Book 1. At the start of Book 2, she has been living on the train as a fugitive from the reflection police. She accompanies Jesse on his journey through the train while struggling with her sense of identity as an independent person, rather than Tulip's reflection or a construct of the train. Upon leaving the train at the end of Book 2, she names herself Lake. Jesse Cosay (Robbie Daymond) is a passenger who becomes MT's friend and helps them escape the train. He is easygoing and friendly, but has a hard time resisting peer pressure; his experience on the train teaches him how to stand up for his friends and his younger brother. Upon initially leaving the train in the middle of Book 2, he returns in order to help MT leave too. Alan Dracula is a magical silent, shapeshifting white-tailed deer, a denizen of the train who accompanies MT and Jesse on their journey, serving as their steed. Guest voices for Book Two include Wayne Knight, Laraine Newman, Nea Marshall Kudi, Bill Corbett, and Rhys Darby.
Book 3 – Cult of the Conductor Grace Monroe (Kirby Howell-Baptiste) is the young adult leader of the Apex, a gang of passengers who aim to raise their numbers to remain on the train indefinitely, and believe One-One to be an impostor who usurped the role of Conductor. After appearing as a secondary antagonist in Book 2, Grace returns as one of the main protagonists of Book 3, in which she gradually begins to see the error of her ways and decides to try to fix her mistakes. Brooke Singleton voices Grace as a child Simon Laurent (Kyle McCarley) is Grace's second-in-command and best friend, who first appears alongside her in Book 2. He is a clinical narcissist who has a murderous hatred of denizens and believes that his actions are justified, due to his past experiences in the train along with Grace enabling his negative impulses. Returning as one of the main protagonists of Book 3, Simon begins to double down on his behavior due to his unwillingness to acknowledge his mistakes and change, resulting in his relationship with Grace slowly deteriorating. After usurping her position as the leader of the Apex, Simon attempts to execute Grace for her betrayal before being killed by a Ghom. Samuel Faraci voices Simon as a child Hazel (Isabella Abiera) is a 6-year-old girl who travels the train. Although she has a number on her hand, it doesn't glow; unknown to her, she is actually a human-turtle hybrid of the train created by Amelia's experiments. Initially cheerful, joyous, and optimistic, she later becomes disillusioned with both Grace and Simon after the latter kills Tuba and the former turns her back on her, leading her to lose trust in her former friends and leave with Amelia. Tuba (Diane Delano) is Hazel's gorilla friend, adoptive mother and protector, a denizen of the train. She distrusts both Grace and Simon due to their differing agendas, albeit begrudgingly assists them on their journey along with Hazel. She is later killed by Simon when he takes advantage of the moving train cars to throw her off the train.
Guest voices for Book Three include Rhys Darby, Edi Patterson, Phil LaMarr, and Alfred Molina.
Book 4 – Duet Min-Gi Park (Johnny Young) is a young man who is hesitant to pursue his dreams of being a musician and feels pressured to live a conventional life instead. Ryan Akagi (Sekai Murashige) is Min-Gi's best friend, who aspires to become a famous musician and tends to make rash decisions. Kez (Minty Lewis) is a sentient concierge bell who accompanies Ryan and Min; her thoughtless behavior has made her many enemies among the train's other denizens.
Guest voices for Book Four include Steve Park, Thomas Lennon, and Donald Faison.
Recurring
The Cat (Kate Mulgrew) is a talking cat who is a collector and con artist, and runs a variety of businesses on the train. In Book 1, she is an unwilling agent for Amelia who attempts to capture the heroes before being betrayed and later assisting them in reaching her. Book 3 reveals that her name is Samantha, and she was Simon's companion when he first boarded the train. (Recurring in Book 1 and Book 3; guest in Book 2 and Book 4)