Sarah finds Doctor gasping at the rock pool

With the escape vessel already lifting off, Sarah stumbles upon the Doctor near the rock pool where he has been collecting his vital positron samples. He is barely conscious, clutching the toffee tin that holds the last of his work. As the ship’s departure means they are cut off from rescue, Sarah desperately tries to rouse him with repeated pleas while the seconds until full abandonment tick away. The Doctor’s fractured warning about Vandervelt’s equation becomes a lifeline—offering a cryptic but critical clue about the antimatter threat that the crew still refuses to acknowledge. His collapse mid-sentence underscores the fragility of their last chance to survive the unfolding catastrophe.