A young girl is killed while walking with her mother when an Upper East Side brownstone explodes. Detectives Ed Green (Jesse L. Martin) and Nina Cassady (Milena Govich) quickly determine that faulty wiring is to blame and their investigation leads to the building owner's ex-wife. But with only circumstantial evidence, it’s difficult for A.D.A.s Jack McCoy (Sam Waterston) and Connie Rubirosa (Alana De La Garza) to prove their case. S. Epatha Merkerson and Fred Dalton Thompson also star.