This play is designed to set and cover the back set to H.
The deception/execution of the two non-hitters (1 and 2) is key to this play.
They must pretend to approach as if to hit but then must immediately take a defensive position.
Once the setter sets back she must rotate to face the back side hitter.
After 2 fakes her approach she immediately moves to cover the hitter.
After 1 fakes her approach she moves to cover any deep hits off the block.