Question

How does Jem realize that Boo Radley was the one who placed a blanket on Scout’s shoulders during the fire?

Answer 1

Atticus then asks, "Then whose blanket is that?" Scout then becomes aware of the blanket across her shoulders. As Jem is remembering the events, he recalls that Mr. Radley was fighting the fire with the other men, which means he could not have been the one to cover Scout with the blanket.