An explosion at the office of a Van Dyke, a close friend of the Dexters. Commissioner Roosevelt send for Frank as Felix Dexter asked that Frank be in charge of the investigation. Sarah goes to her family to help and finds her Mother there. Frank is astonished and dismayed to find Sarah there. The eldest son has taken up with the anarchists and many feel he is responsible for the bomb. His stepmother insists he is guilty. Against Frank’s wishes, Sarah and her Mother seek out the terrorists in lower East Manhattan. The ending will surprise you.