Why does the man in the yellow suit go to the Fosters? What does the constable's remark about the gallows seem to predict for the Tucks?
The man in the yellow suit goes to the Foster household to blackmail them. The Fosters know that Winnie is missing. They do not know if she has run away or been kidnapped. The man in the yellow suit goes to the Foster home to tell them that he knows where Winnie is and who has her. The Fosters are immediately relieved that this seeming good Samaritan is willing to help them out; however, they quickly discover that the man in the yellow suit has a hidden agenda. He wants to own the woods that the Foster family owns. He will tell them where Winnie is, if they give him the woods in return.
"I've got what you want, and you've got what I want. Of course, you might find that child without me, but . . . you might not find her in time. So: I want the wood and you want the child. It's a trade. A simple, clear-cut trade."
The Fosters agree to the trade, and the constable is immediately brought into the situation.
The man in the yellow suit and the constable both begin riding toward the Tuck home. The constable is a talkative man, and so he begins trying to strike up a conversation with the man in the yellow suit. At one point, the constable mentions the gallows.
"'Course, we got a gallows of our own, if we ever need it. Keeps down trouble, I think, just having it there. Ain't ever used it yet."
The constable's remark about the gallows foreshadows the coming trouble to the Tuck family. The reader learns that the town has a jail and a gallows. The gallows information is a useless extra detail, unless for some reason it will be important. After Mae kills the man in the yellow suit, the gallows becomes a deadly important part of the story.