Aspiring writer Lester Grimm finds himself in a whirlwind romance with Ramona Ray, thanks to an introduction by his friend Vince and Vince's fiancée Lucretia. The two hit it off instantly, but during their very first date, Ramona mentions her famous ex-boyfriend, the acclaimed writer Dashiell Frank. This revelation stirs a hint of jealousy within Lester.
One fateful day, Lester observes Dashiell wandering down the street and, driven by curiosity, decides to follow him. To his surprise, he discovers that Dashiell attends group therapy sessions. Intrigued, Lester joins the group under the pretense of being Vince, which sets off a series of tumultuous interactions between him and Dashiell. During these therapy sessions, Dashiell confides about his infidelity issues while Lester interjects with surprisingly frank criticism that stuns the group.
As time passes, Lester contemplates leaving the therapy group, much to Vince's dismay, since Vince had wished Lester would share personal insights with him. Ultimately, Vince persuades Lester to stick around for a couple more sessions, where their contentious dynamic continues to spark tension. In a gripping session, Dashiell talks about a character inspired by someone real, hinting at Ramona being the muse.
Despite claiming he would leave, Lester stays involved with the therapy group. After one particular session, Dashiell invites Lester out for a drink, and they bond over scotch as Dashiell expresses his appreciation for their heated discussions. However, in a slip of memory, Lester misses a planned meeting with Ramona, leaving her unaware of his growing friendship with Dashiell. Later, he lies to Ramona about attending a screening of The Man Who Shot Liberty Valance, claiming it was in color—a falsehood that eventually backfires.
Dashiell's invitation to his home introduces another pivotal character, Irene, Dashiell’s girlfriend. Following this, a vulnerable moment unfolds between Lester and Ramona as she discloses her past with an ex-boyfriend, Steven, suggesting that her previous relationships hold little significance now.
Dinner reveals more of Ramona's past, and tension escalates between her and Lester, questioning Dashiell's claims about a character based on her. Complications arise when Vince joins the therapy sessions, disguising himself as ‘Leo’ with a faux British accent while revealing Lester's personal struggles to the group without consent—infuriating Lester.
The drama culminates when Dashiell admits to having an affair with Ramona. Frustrated, Lester stormily confronts her outside, triggering a public unraveling of their lies and culminating in a heated fight with Dashiell, claiming, > “She's my girlfriend," before they part ways in anger.
Months later, we find Lester at the Iowa Writer's Workshop, deeply engrossed in his writing, while Ramona seeks therapy with Dr. Poke back in New York. The narrative comes full circle at Vince and Lucretia’s wedding where chance brings Lester and Ramona back together. In a poignant moment, he extends his hand, inviting her to dance. Though she hesitates at first, reflecting on her journey to heal from their past, she ultimately accepts, signaling a flicker of hope for their relationship.
