On the afternoon of May 7, 1915, a German torpedo struck the passenger liner, RMS Lusitania. Seconds later, a massive 2nd explosion rocked the ship. Within 20 minutes, the so-called "Greyhound of the Seas" was at the bottom of the ocean ... and nearly 1200 innocent men, women and children were dead. Now, a new two-step investigation has been launched to determine what exactly sank the Lusitania. The end result is a remarkable journey through the shadows of history - one that may finally reveal the Dark Secrets of the Lusitania.