Dump goes upline. If it's open, hit it.
If not, he clears to the back. Front of the stack drives back like he's going to receive an around dump from the thrower.
Person who was originally at the front of the stack but is now in the backfield goes upline. If it's open, hit it.
If not, he clears to the back of the stack. Current front of the stack provides a bailout reset.