How did mcmurdo trapped the scowers

McMurdo and McGinty speak about the trap they are setting. McGinty frets over whether or not McMurdo has already told anyone anything. He wonders if Morris is involved; McMurdo tells him it is unlikely, but they have to focus on Edwards right now anyway. He then proceeds to explain how the plan will work: Edwards comes to the house at ten that night; the Freemen hide while he puts Edwards at his ease; he then jumps on Edwards and holds him until the others rush in. McGinty likes the plan and compliments McMurdo.