An ordinary outing takes Greta, Alex and four-year-old Smilla across Sweden's mythical Lake Malice to a tiny, isolated island. While father and daughter tramp into the trees, Greta stays behind in the boat, lulled into a reverie by the misty, moody lake, only later to discover that the two haven't returned. Her frantic search proves futile. They've disappeared without a trace. Greta struggles to understand their eerie vanishing. She desperately needs to call Alex, to be reassured that Smilla is safe, or contact the police. But now her cell phone is missing too. Back at her cottage, she finds it hidden away under the bedsheets. Had she done that? Or had someone else been in the cottage? But who, and why? As Greta struggles to put the pieces together, she fears that her past has come back to torment her, or she's finally lost her grip on reality.