Russell and Finlay find themselves facing a harrowing blast from their past as they tackle a chilling serial killer case in the bustling city of Seattle. Just when they think they have put the horrors behind them, a new wave of terror grips them when a copycat killer emerges in the dazzling streets of Las Vegas. With their own personal demons resurfacing, they must delve into the twisted minds of these murderers and unravel the unsettling connections between their past and present. Can Russell and Finlay unravel the web of darkness before it claims more innocent lives? The stage is set for a heart-stopping tale of justice and redemption in "Echoes of Sin".