Things heat up when McQueen is sent to investigate a body found in the rubble of a fire and meets FDNY Fire Marshal Mason Willis. Willis is investigating it as an arson, but the medical examiner's report makes it obvious that this is a case for McQueen. McQueen and Willis have no choice but to work together. Will even the combined efforts of the NYPD and the FDNY be able to stop the killer... or killers?