FBI Special Agent Katie Winter is no stranger to frigid winters, isolation, and dangerous cases. With her sterling record of hunting down serial killers, she is a fast-rising star in the BAU, and when a woman is discovered in the middle of a frozen lake, Katie is the natural choice to partner with Canadian law enforcement to track the killer across the brutal and unforgiving landscape. But tensions run high between Katie and her new Canadian partner, and time is running out before the killer’s trail goes cold. The case also conjures the demons of her own past: Katie’s younger sister, vanished years ago on the shore of the very same lake, a case that remains unsolved. Can Katie keep her demons at bay long enough to enter a killer’s mind and stop him before it’s too late? Or will this diabolical monster outwit her in his game of cat and mouse?