* CompleteMonster - The Earl of Upnor has no redeeming qualities whatsoever. The other bad guys might be AffablyEvil, might be {{Magnificent Bastard}}s, might have [[WellIntentionedExtremist sympathetic motives]], or might [[EvenEvilHasStandards have standards]]. But not Upnor. Upnor is a nasty, vile, evil sack of scum who exists solely to make the reader hate him.
* CrazyAwesome - Jack and Jeronimo walk a fine line between sanity and insanity and are really awesome because of it.
* EpilepticTrees - Tons of them involving the Solomonic Gold and the true nature of [[spoiler:Enoch the Red]].
* NightmareFuel - Daniel's kidney stone operation and the story of how Jack became "Half-Cocked". The descriptions of the effects of smallpox and the attention paid to 17th/18th-century sanitation (or the lack thereof) probably count as well.
** In-story, Hooke and Wilkins' experiments at Epsom provide Daniel with this.