[s0e13] Planet Of The Dead -

They raced back to the bus. While the Doctor reconfigured the engine using his sonic screwdriver and Christina’s stolen trinkets, the passengers stepped up. Nathan used his knowledge of structural engineering to help brace the chassis, and Angela kept everyone calm, distributing what little water they had.

to other "one-off" companions like Astrid Peth.

"They tear a hole in space, eat the world until it's a desert, and then move to the next one," the Doctor explained, his eyes widening. "And that hole leads straight back to London." [S0E13] Planet of the Dead

Beside him, Lady Christina de Souza brushed dust off her expensive leather jacket. She didn't look terrified. She looked bored.

(or sci-fi logic) behind the "Stingray" creatures. They raced back to the bus

"A trillion people lived here a year ago," the Doctor said softly. "Then something came. Something that eats everything. Not just the people, but the air, the water, the very molecules of the world."

The bus crashed down onto the wet asphalt of a London tunnel. Police sirens wailed in the distance. The passengers cheered, weeping with relief. to other "one-off" companions like Astrid Peth

The Doctor grinned. "I like your spirit. But the bus is our only way back, and its wheels are buried. We need power, we need lift, and we need it before that swarm hits."