On a beautiful April morning, San Francisco PD Homicide Lt. Lindsay Boxer is out jogging with her dog when a house explodes right in front of her. Instincts kicking in, Lindsay races into the house and rescues a young boy, the only survivor. The house was the home of an Internet billionaire, and a mysterious message is left behind which baffles the police. They&apos,re also investigating the disappearance of an infant from the house, the youngest child of the family. There were three bodies found in the house, but they were all adults.