Bike messenger Caleb Shimansky is killed by a masked man in a stolen black sedan. Caleb carried only one package, for Sally Niedermeyer, whose name the courier firm had miswritten as terrorist Shakir Nidal Mattar's. It was a message from her nephew Brian Thompson, from jail, where he's murdered hours later. It proved he, convicted due to present captain Roy Montgomery, confessed innocently to have his son's medical bills paid. Castle's connections help investigating the original murder of Olivia, which soon points to the extremely wealthy, politically influential Wellesley family, but which one and why?