Blake's dead. They say his wife killed him. If so... which one?

Polygamist Blake Nelson built a homestead on a hidden stretch of land—a raw paradise in the wilds of Utah—where he lived with his three wives:

Rachel, the first wife, obedient and doting to a fault, with a past she'd prefer to keep quiet.
Tina, the rebel wife, everything Rachel isn't, straight from rehab and the Vegas strip.
And Emily, the...