Narrator presents the slow-burning life of Charlie, a man living in Moscow, Idaho, who spends early 2016 teaching online English writing courses to college students but keeps his webcam off because he is ashamed of his morbid obesity. He isolates himself in his apartment, rarely stepping outside, while his nurse and sole confidante, Liz, acts as both caretaker and catalyst—bringing him meals that are unhealthy even as she urges him to seek hospital treatment for heart problems he claims he cannot afford.
Charlie's world is a routine battlefield: nightly pizza deliveries become a ritual, with Dan the delivery driver leaving the pie on the porch and collecting payment from the mailbox; the two never meet face-to-face, reinforcing Charlie's sense of separation from the world. He clings to a fragile hope to reconnect with his estranged teenage daughter Ellie, who he abandoned eight years earlier when leaving his wife, Mary, for a male student named Alan. In a troubling bid to regain a place in her life, Charlie offers Ellie the entire sum of his savings—$120,000—provided she spends time with him without her mother's knowledge. Ellie agrees, but on the condition that Charlie does all of her homework and keeps a notebook of her writing, a request that hints at the complicated dynamic between them.
As Charlie's health deteriorates, Liz supplies him with a wheelchair to help him stay mobile, yet the underlying fragility of his body remains ever-present. A second visit from Thomas, a missionary for the New Life Church, complicates matters: Liz initially ejects him, but then explains her complicated past—she is the adopted daughter of New Life's head pastor, and Alan's death by suicide stems from religious guilt born of their family’s faith. Charlie's weight and emotional struggles are revealed to be tied to these painful memories, and Liz’s objection to Thomas’s persistence softens only a little as Thomas persists in his mission to help Charlie.
The pressure mounts when Ellie compromises the fragile arrangement by drugging Charlie with crushed Ambien and filming him as he and Thomas smoke marijuana. Ellie records their conversation, exposing more about their lives than Charlie anticipated. Concerned, Liz brings Mary to visit Charlie, and Mary and Liz clash over Charlie’s deception and the money he’s saved for Ellie, while Mary confronts the hurt caused by Charlie’s past choices and his decision to leave his family for Alan.
That night, after another delivery in the rain, Dan witnesses Charlie for the first time and leaves shaken. Charlie then experiences a severe binge-eating episode and fires off a profane, unhinged email to his students, telling them to skip classwork and simply write him back with something honest. Thomas returns one last time to tell Charlie he is returning home after Ellie’s action—her confession has reached his former youth group and family, who have forgiven him and urged him to come back. In his final act of defiance, Thomas tries to invoke Romans 8:13, but Charlie rebukes him for blaming Alan’s death on his sexual orientation and orders him out.
In Charlie’s next class, he announces that he is being fired for the email, then shares a few of the student submissions. To honor their raw honesty, he switches on his webcam for the first time. The class’s reactions range from stunned to hopeful as he declares that academics do not truly matter, but the honest thoughts of his students do. He abruptly ends the session by flinging his laptop against the fridge, destroying it.
Liz returns to support Charlie as his health rapidly worsens. Ellie arrives to confront him about a failing grade she received on an essay he allegedly rewrote for her, which he secretly replaced with a piece she wrote in eighth grade about Moby-Dick—the essay he calls the most honest he has ever read. Ellie initially lashes out, but as she reads the work aloud at Charlie’s urging, a moment of reconciliation seems possible. Charlie rises to walk toward her without assistance for the first time, and they share a quiet, hopeful smile. In that moment, Charlie begins to levitate, enveloped in a radiant, white light, signaling a final, transcendent turn in his story.
