Devil In The White City
Non-fiction account of
activities of Serial Killer HHHolmes in Chicago at the same time
Enjoyed the underlying story of the Fair, but the writing ranges from flat to hugely irritating. The flash-forward tidbits ("only later would the world realize...") are just 1 step above "it was a dark and stormy night".
See also 2007-01-06-JohnsonInterview.