July 26, 2009. A Ford Windstar minivan enters the Taconic State Parkway shortly after 1:30pm and accelerates to a speed of 85 mph ... going the wrong way into oncoming traffic. Behind the wheel is 36-year-old Diane Schuler, high on marijuana with a blood-alcohol level of .19, more than twice the legal limit. She's out of control, weaving around cars with a bottle of Vodka next to her and 5 children as passengers. The terror continues for 1.7 miles, until the van collides head-on with an SUV, killing everybody but Diane's 5-year-old son, Bryan. In the aftermath, an investigator reveals conversations with more than 50 family members and friends proves nobody had ever seen Diane drunk, or even consume more than a single drink. So, what pushed this responsible, loving mother over the edge? A panic attack? A stroke? Or was it something more sinister?