Locked in a wheelchair genius criminologist Lincoln Rime, along with his student and assistant Amelia Sachs investigate an unusual case: after a failed attempt, an assassin continues to pursue a high school student from Harlem. Who and why hunts for an ordinary schoolgirl who writes a course paper about her ancestor - a former slave Charles Singleton, who fought for the rights of African Americans? The only clue left at the scene of the assassination is the twelfth card of the Tarot "Hanged" . Together with his team, Ryme and Sacks try to calculate the next step of the mercenary and at the same time find out what happened on the July night of 1868, when Singleton was arrested. What painful secret did he hide?