What happens when widowed Molly Donovan hides from her grief in the family cabin only to discover her recently passed husband's secret?

Recently widowed Molly Donovan, 55, finds herself adrift in a sea of grief as the harsh New England winter sets in. But when her best friend suggests they spend the winter at Molly's family cabin on Moose Pond, she finds a glimmer of hope in the form of a retired marine biologist.

One day, while rummaging through her husband's old desk, Molly stumbles upon a tattered map marked with a series of locations around the pond. Curiosity piqued, she embarks on a journey to unravel the mystery, with her handsome neighbor as her steadfast companion. But with each stop on the map, Molly uncovers more and more about her late husband that makes her question their entire marriage.