In the third season finale, Audrey, Nathan and Duke square off against the Bolt Gun Killer and Audrey's own tragic fate.
As Audrey's health deteriorates, Nathan races to find a cure for the mysterious illness before it is too late.
As Duke's volatility threatens to unleash unprecedented chaos on Haven, the pressure is on for the CDC doctor to develop a cure for the troubles.
Charlotte makes progress towards developing a cure for the troubles, but it might be too late as Duke's condition takes a turn for the worse.