Despite severe rationing and around the clock security, the water reserves on board the Destiny continue to drop. Dr. Nicholas Rush has no explanation for this latest setback but, if they are to survive, they must find a new water source soon. The only planet within range is a frozen wasteland surrounded by a thin and poisonous atmosphere. Donning two of the ship's deteriorated spacesuits, Col. Young and Lt. Scott head to the planet's surface, hoping to retrieve enough ice to replenish their water supply. But once there, tests reveal that the ice near the Stargate contains traces of highly toxic chemicals. Young and Scott take off in search of drinkable samples knowing they don't have long before their air will run out and Destiny jumps back to FTL.
Back on board the ship, Lt. Tamara Johansen works with the crew to catch an intruder they believe is responsible for the lost rations.