NCIS: Season 4, Episode 24

4 - 24: Angel of Death

Jenny returns from her European trip and discovers that she had an unannounced visitor at her home who she suspects is her supposedly dead father. All NCIS agents are scheduled to take a Homeland Security polygraph test, which Gibbs finds out to have been arranged by the CIA. An unarmed Tony and Jeanne are held hostage in the hospital morgue by a drug dealer, who is desperate to remove his shipment of drugs from the dead