Elizabeth forced herself to sit straighter against the bulkhead and blinked again to clear her vision. In the half-darkness of the wrecked jumper, she could still see the moment when Sheppard began to regain consciousness. She felt the breath catch in her throat and was sure that her heart was loud enough to be heard even in the rear compartment of the Ancient spacecraft.

Her hands were slick with sweat on the borrowed energy pistol. She knew what she had to do. The throbbing of the cut above her left eye and the sticky feeling of the blood caked on her eyelid, where it had run down, were reminder enough that when the time came she mustn't hesitate.

The man in front of her, whom she had long considered not just a colleague, but a friend, groped his way upright, with uncoordinated limbs. Elizabeth shrank away from him, pressing herself closer to the bulkhead, and gripped the pistol more tightly. Not daring to blink, she kept her eyes fixed on his shadowed face.

Remember, leave it as late as you dare – every shot weakens Sheppard, just as it weakens them. She replayed McKay's hurried advice, shouted through the barrier hours before, and prepared herself to do what needed to be done.

Sheppard finally raised his head to look at her. His eyes – usually full of life and a warm hazel - were blank with dull silver, and her stomach lurched with nausea. Not daring to breathe, she raised the pistol, and waited until she saw him tense to spring. She squeezed the trigger, and Sheppard was enveloped in crimson light, arching his back in obvious agony before curling in on himself and crumpling awkwardly to the floor.

Elizabeth counted slowly to ten, trying to slow her breathing, before cautiously pushing herself upright and crawling the short distance to the unconscious body of her friend. She raised one hand to his neck, and allowed herself a shaky breath of relief as the steady thrumming of a heartbeat greeted her fingers. She scooted back to her corner and closed her eyes for a brief moment, knowing that this is all that she could allow herself.

How many more times would she have to do this before Rodney found a solution, or rescue arrived? And how many times could John Sheppard survive it?