In a not-too-distant future where climate change has dramatically altered Miami, rising seas have forced the populace to live under the cover of night, while the blazing sun reigns during the day. Amidst this unforgiving environment, Nick Bannister, played by Hugh Jackman, and his friend Emily "Watts" Sanders, portrayed by Thandiwe Newton, run a unique business that enables clients to revisit their memories.
One fateful day, a mysterious woman named Mae, acted by Rebecca Ferguson, enters their lives seeking assistance in locating her lost keys. As Nick experiences Mae's memories, he becomes enchanted, discovering that she is a nightclub singer whose haunting rendition of "Where or When" particularly resonates with him, deepening their connection. However, not everyone is convinced of Mae's good intentions. Watts harbors suspicions, cautioning Nick about this new romantic interest.
DA Avery insists Nick help investigate Walter Sylvan, played by Brett Cullen, a land mafia leader implicated in the suspicious fire that ravaged a tenement. However, Sylvan's attorneys argue his declining health makes him unfit for the memory retrieval process. As the months pass, Mae inexplicably disappears, leaving Nick in turmoil. While Watts attempts to rationalize her absence as a move on, Nick fears she may be in peril. To uncover the truth, he obsessively revisits fragments of their shared past—dangerously blurring the lines of reality.
In his efforts, Avery Castillo (Natalie Martinez) enlists Nick and Watts to extract memories from a comatose criminal linked to a notorious drug lord named Saint Joe (Daniel Wu). During these harrowing sessions, Nick uncovers painful secrets: Mae once belonged to Saint Joe and had succumbed to the clutches of Baca, a ravaging narcotic, ultimately stealing his stash and fleeing. This knowledge shatters Nick, amplifying his feelings of betrayal and despair.
Traveling to New Orleans, Nick confronts Saint Joe, only to be ambushed by his thugs. However, Watts comes to his rescue, leading to a violent conclusion where they eliminate their enemy's reign of terror. Returning to Miami, Nick urges Watts to revisit her last encounter with Mae, discovering that Mae had previously hacked into their memory archives, stealing recordings that could expose a web of deceit involving Elsa Carine (Angela Sarafyan) and Walter Sylvan.
As Nick delves deeper into this dark mystery, he learns that Elsa was murdered, and her son is missing, possibly kidnapped by Mae. In one encounter, he faces Cyrus Boothe (Cliff Curtis), a former henchman turned corrupt cop, now entangled with Sylvan's operations. As Watts expresses her love for Nick and urges him to reconsider the depth of his obsession, Nick, determined to uncover Mae's whereabouts, dismisses her concerns.
With revelations swirling around him, Nick discovers that the child he seeks is markedly tied to Sylvan’s family lineage. Using information from Sylvan’s widow Tamara (Marina De Tavira), Nick embarks on a relentless pursuit that leads to an explosive confrontation with Boothe. Determined to piece together Mae's motives, he subjects Boothe to the memory machine, only to learn that Mae's initial feelings were rooted in a ruse—a manipulative scheme to seduce him. Yet, as the memories unfold, it becomes evident that Mae's feelings for Nick grew genuine over time.
Ultimately, Mae faces a tragic turning point, delivering a poignant farewell too late before consuming a lethal dose of Baca and plunging into the void. Racked with grief, Nick condemns Boothe to relive his most painful memories, enacting his own form of twisted justice. In the final strands of his journey, Nick confronts Sebastian Sylvan (Mojean Aria), unraveling a tragic tale of greed and desperation.
Ultimately, Nick reveals to Watts his heinous act of burning Boothe's memories. Although he is punished for his crime, he chooses to immortalize his time with Mae, spending his days trapped in nostalgia. In these memories, he softly recounts their love story, mirroring the tale of Orpheus and Eurydice, hoping against hope for a reunion that transcends the confines of their harrowing reality.
