Thunderstruck starts slowly, with the connection between Marconi and Crippen only becoming clear in the book's riveting final quarter, when Marconi's system proves instrumental in capturing Crippen and his mistress. This happens when the two conspirators attempt to escape onboard the ocean liner Montrose, even though the ship's captain has seen through their disguises and secretly keeps Scotland Yard informed of their actions via telegraph. As the chief inspector on the case sprints across the Atlantic in a faster ship to intercept Crippen, the entire story plays out across newspapers worldwide.
Interestingly, Thunderstruck ends up being an inversion of The Devil in the White City, where the sociopathic murderer Dr. H. H. Holmes is contrasted with the visionary architect Daniel Burnham, and it's always clear where the author's sympathies lie. By the end of Thunderstruck, Marconi doesn't come off very well. A workaholic who routinely screws his partners, he initiates scandalously public feuds on the level of Paris Hilton/Lindsay Lohan. Perversely, Crippen becomes almost endearing by comparison.
The troubled inventor Marconi is a perfect candidate for Larson's facility with all things technical, and the disparity between the meek Crippen and the brutality of his crime has fascinated the likes of director Alfred Hitchcock and novelist Raymond Chandler. In fact, it's probably Chandler's spot-on summation of Crippen -- quoted by Larson -- that illustrates the real reason this tale has survived for so long: "You can't help liking the guy somehow," wrote Chandler. "He was one murderer who died like a gentleman."