A four-month-old baby is found dead in his crib. Not only must Dr. G find out what caused this baby's untimely death, she must also find out if the baby's twin sister is also at risk of dying in the same manner. A 23-year-old father collapses on the floor while at home with his children. Because of the man's age and history of marijuana use, Dr G. suspects that he may have used and subsequently overdosed on harder drugs. (thetvdb.com)