S9, E4: The sudden death of a kindergarten boy from a rare and lethal flu sends Detectives Briscoe (Jerry Orbach) and Curtis (Benjamin Bratt) frantically searching New York City for the source of the virus. They quickly realize the young boy contracted the flu through lethal injection, and Assistant District Attorneys McCoy (Sam Waterston) and Carmichael (Angie Harmon) must link the murderers to the source of the deadly serum and bring them all to justice before another potential outbreak. S. Epatha Merkerson and Steven Hill also star.