Jack McKinney retired from the police force 5 years ago, hoping to finally relax after a demanding career catching criminals. But his peace is shattered when his beloved granddaughter Emma mysteriously vanishes shortly after joining him on a camping trip. Jack knows there was tension between Emma and her father Ethan-Jack's son-who disapproved of Emma visiting her grandfather after his early-onset Alzheimer's diagnosis.

Desperate to find Emma before his memory fails him completely, Jack begrudgingly asks Ethan for help retracing their steps in the woods. The investigation dredges up painful memories and secrets that drove the family apart. As more clues point to Emma not running away but being taken captive, Jack races against the rapid progression of Alzheimer's to rescue her using his fading detective skills.

Scouring the isolated campsite, Jack uncovers inconsistencies he had missed. But the short-term memory lapses caused by Alzheimer's stymie his progress. It's only with Ethan reviewing Jack's old case notes that promising leads emerge. As they unravel the past, father and son mend their strained relationship while confronting Jack's guilt over his imperfect recollections and police work.

Closing in on Emma's whereabouts, Jack must push past the fog of dementia to solve this one last case. Will he rescue his granddaughter with the last intact threads of his once-brilliant mind before she meets a tragic end?