The life of a hitwoman isn't what she presumed...

Mercy settles in a small town in Alabama as she tries to put the pieces of her life back together and deal with the irreparable damage to her brain. With every kill, she sleeps a little better, but something inside her is definitely broken.

Seeing the warning signs...

Special Agent Murphy Morgan keeps tabs on Mercy, against the wishes of her partner and a direct order from the Director. Morgan, however, is convinced Mercy is about to snap.

Who will win this battle of wits? Will Morgan bag a serial killer before she starts or will Mercy always be one step ahead?