Battlestar Galactica - Season 1 Episode 1

The Galactica and the other remaining ships – with about 50,000 people aboard them all – are being pursued by the Cylons. They are forced to jump into hyper space every 33 minutes. Somehow, the Cylons know where they are going and appear exactly 33 minutes after the Galactica arrives. The crew hasn't slept for over 130 hours now and everyone is exhausted. They rejoice when they finally make a jump and the Cylons fail to appear at the 33 minute mark. They are also prone to make mistakes and realize they've left behind a ship, the Olympic Carrier, with 1300 passengers aboard. When the ship rejoins the fleet a few hours later, the Cylons again arrive 33 minutes later leading Adama to conclude that there are Cylon spies on board. President Roslin now faces a major decision. The identity of the the Cylon aboard the Galactica is revealed.