The story opens with a prologue set in Provence, France, at an unspecified future point. Elijah Iverson, a journalist, watches a naked Aiden Bell sing psalms on a mountainside, struck by the contrast between the contemplative monk before him and the chaotic millionaire Aiden once was. Elijah reflects that there is no instruction manual for falling in love with your best friend's little brother, or for falling back in love with him when he is a monk.
The narrative shifts to Aiden's perspective at Mount Sergius Abbey, a Benedictine monastery in Kansas. Now called Brother Patrick, Aiden wakes from an erotic dream about Elijah, his ex-boyfriend. He has been a monk for four and a half years, having arrived after a crisis that nearly cost him his life. Once a reckless millionaire, he has become punctual, serious, and rarely speaking, yet he has never stopped loving Elijah. Brother Connor, his mentor, brings him to Abbot Jerome, who offers Aiden the chance to visit three Trappist monasteries in Europe to discern whether a stricter monastic order might suit his restlessness. Among the options is St. Columba's, a cliff-side abbey on Ireland's west coast that immediately captivates him.
Before Aiden can absorb the offer, he learns he has a visitor. In the cloister he finds not his brother Sean but Elijah, visually transformed. Observing a temporary vow of silence, Aiden can only listen as Elijah explains that he sold the farmhouse Aiden left him, became a staff writer for
Mode magazine, and is engaged to a man named Jamie. Elijah tells him, "I loved you for a long time after you left" (34), implying he no longer does. Aiden retreats to the hermitage, a small cottage two miles from the main abbey, and breaks down. He confides in Brother Connor, then decides to take the trip, interpreting his feelings as proof he needs more austerity. At the abbey, Aiden had begun therapy with Dr. Rosie and processed his sister Lizzy's death by suicide following sexual abuse by their parish priest. This work led him to found Lectio Lexapro, a support group for monks living with mental health conditions.
Weeks later, Elijah returns to research an article about monastic brewing. Abbot Jerome assigns Aiden as his host, reasoning they are practically family through Sean's marriage to Zenny. A burst pipe forces Elijah into the dormitory cell next to Aiden's. While showing Elijah the grounds, Aiden notices a new tattoo on Elijah's forearm. At the hermitage, Elijah angrily calls monastic life "a waste of a life" (98), accusing Aiden of wasting his privilege. That evening, however, they sit together watching the annual firefly display in the cloister. Their faces draw close, and they nearly kiss before approaching monks break the spell.
Elijah apologizes the next day, and his fiancé Jamie, a librarian, visits the abbey. That night, Aiden hears Elijah through the thin wall and touches himself through his chastity cage for the first time in years. Days later, during a thunderstorm at the hermitage, Elijah confesses he returned not just for the article but to try to forget Aiden. They kiss against the wall, and Elijah discovers Aiden's chastity device. When Jamie calls, the reality crashes in, and Elijah flees without saying goodbye. Aiden confesses to Abbot Jerome, who urges him to use the upcoming trip to examine what he truly wants. The abbot reveals Elijah has requested to join the trip, and Aiden agrees, determined to resist temptation.
In Belgium, they spend five days at Semois Abbey in the Ardennes, where grueling Trappist silence leaves little room for conversation. Aiden finds the monastery uninspiring. On their last day, they picnic in the forest, trading stories of parallel transformations: Aiden from hollow finance to meaningful monastic labor, Elijah from event planning to writing at
Mode. Exploring medieval ruins, they give in to desire. Aiden proposes an erotic "what if" game, their shared language for fantasies, and performs oral sex on Elijah. That night, Elijah comes to Aiden's room and gives him a hand job without speaking.
They travel to Our Lady of the Fountains, a sunny Provençal abbey in a lavender-filled valley. On the train, Aiden reads Elijah's forearm tattoo:
Quid si, Latin for "what if." Aiden helps with the lavender harvest, discovering that praying wherever he stands in the fields feels more natural than rigid schedules. In a deconsecrated hilltop chapel, they have penetrative sex for the first time, and Aiden feels no separation between loving Elijah and loving God. Elijah reveals he ended his engagement to Jamie before the trip. Both acknowledge their love but understand the relationship must end when they return home. A chance encounter with Father Jordan Brady, the parish priest of Sean and Zenny, unsettles Aiden. Father Jordan tells him that keeping secrets from loved ones gains nothing, and Aiden realizes the priest means the suicidal ideation he has never told Elijah about.
In Ireland, they reach St. Columba's, the austere sea-cliff abbey Aiden had set his heart on. After two days without privacy, Aiden leads Elijah beneath a yew tree and tells the complete story: how depression shadowed him since his sister's death, whispering for fifteen years that the world would be better off without him; how the night of their fight the darkness overtook him; and how a mysterious text of Psalm 121 at 3:28 a.m. saved his life. Therapy, medication, and monastic life rebuilt him.
The next morning, Aiden resolves to leave the abbey and choose Elijah. In a ruined cliff-side cottage, he tells Elijah his plan. Elijah says he loves Aiden "like everything," and they make love on the grass. But the following morning, Elijah is gone. A letter explains that he now understands why monastic life saved Aiden and will not be the reason Aiden abandons it: "I can't compete with fireflies in the cloister. Please don't make me try" (359).
Back at Mount Sergius, Aiden withdraws for weeks. Brother Connor tells him there are "many ways to the well" (377), suggesting more options exist beyond staying or leaving. Jamie visits with a copy of
Mode containing Elijah's article, which meditates on patience as the quality behind good beer and good love. Aiden calls his brother Tyler, a former priest now married, who challenges his thinking: God can be found outside a monastery. Aiden asks to speak with Abbot Jerome.
Two months later, Aiden has left the abbey. He lives at his father's house, works at Sean's nonprofit, and prays the daily hours at Father Jordan's church. He approaches Father Jordan about creating new forms of liturgical life for those who do not fit existing structures. When Aiden texts Father Jordan's number, he discovers it is the same number that sent him Psalm 121 five years earlier.
At Sean's gala, held at the venue where Aiden and Elijah first came together years ago, Aiden recreates their original flirtation. In the opera auditorium, he tells Elijah he left the abbey eight weeks ago, is stable under Dr. Rosie's care, and is helping Father Jordan build something new. He tells Elijah, "You bring me closer to God...simply by existing" (403). Crying, Elijah asks how he can know it will last. Aiden answers with Elijah's own word: patience.
In an epilogue written as a
Mode article, Elijah describes their wedding at the same venue. Tyler officiates. The monks of Mount Sergius cry harder than anyone. Elijah closes: "I already love him like how forever feels. I already love him like eternity is in the rearview mirror. I love him like everything" (406).