The phones are down. The power is out. One of the most terrifying tropical storms the US has ever seen has arrived! When tropical storm Allison crashes down on Houston, the city is brought to a standstill by the torrent of rain, winds and flooding. Inside a beleaguered hospital, a team of doctors and nurses fight a desperate battle to keep their patients safe. But with emergency manpower stretched to the limit, the next 14 hours will test their endurance as the storm unleashes nearly 30 inches of rain on the battered city.