Yep! Thief 2 knows that thief 1 will surely accept if thief 3 is allowed to make the plan. So he will not allow thief 3 to make the plan because in this case he will get NOTHING at all. He will not allow this to happen- he will not allow thief 3 to plan. Therefore as long as thief 4 gives him anything at all, he will accept.
Get the idea??? So what should thief 4 suggest???