When a desperate woman comes to Daniel Pitt seeking a lawyer for her boyfriend, Rob Adwell, Daniel is convinced of the young man's innocence. Adwell has been accused of murder and of setting a fire to conceal the body, but Daniel is sure that science can absolve him--and Miriam fford Croft is the best scientist he knows. Miriam connects Daniel with her former teacher Sir Barnabas Saltram, an expert in arson, and together, they reveal Adwell's innocence by proving that an accidental fire caused the victim's death. But it's not long before Adwell is killed in the same fiery fashion. If these deaths are, in fact, murders, what essential clue could Daniel and Miriam have missed?

As their investigation deepens, one of Saltram's former cases comes into question, and Miriam finds herself on the defensive. If the reasoning Saltram used in that case is proved false, several other cases will have to be re-tried, and Saltram's expert status--not to mention Miriam's reputation--will be ruined. Haunted by Saltram's shady tactics in and outside of the classroom, Miriam is desperate to figure out truths both past and present and protect herself in the face of Saltram's lies. What started as an accidental fire in Adwell's case seems to be linked to a larger plot for revenge, with victims accumulating in its wake, and Miriam and Daniel must uncover who or what is stoking these recurring flames--before they, too, find themselves burned.