The book is written in a straightforward style but there are medical, computer and timed references that could be confusing to some readers. One of the women on the EROS system is named "Eleanor Rigby." The Beatles had a hit with their song about her and it's that connection that makes Harper at one point even more concerned about "Eleanor" than he had been previously because of the killer's use of the online name, "Maxwell." The reference is explained to some degree but readers unfamiliar with the Beatles' song that describes the action of "Maxwell Edison" may not get the full impact of that connection. In that song, "Maxwell's silver hammer" comes down on the head of several women.