How does the author use foreshadowing in Blood and Chocolate?

When Vivian meets Aiden's parents, he shows her his father's gun collection. His father enjoys buying and refurbishing antique guns, and he makes his own bullets to fit them. The guns serve as a symbol that even humans can be hunters and predators, and that they can be very dangerous when provoked. Aiden isn't yet aware of what Vivian really is, but if he finds out, the reader is unaware of how he will react. In his father's basement, Aiden has the means to make his own bullets, and so could create silver bullets. He also has the guns with which to fire them. Since silver bullets are one of the few things that could actually harm Vivian, this incident adds an uneasy, threatening tone into the novel and foreshadows things to come. Vivian will later find herself facing one of these very guns, with silver bullets inside.