Doctor Who: The Seeds of Death (TV)

The TARDIS brings the time travellers to Earth in the 21st Century, where they learn that human society is now reliant on T-Mat - a matter transmitting device that beams people and freight instantly to destinations all around the globe. The system is currently malfunctioning and the travellers agree to pilot an obsolete rocket to the Moon relay station to investigate. They find the place overrun by Ice Warriors, who are preparing for an invasion attempt. To weaken Earth's resistance, the Warriors are using the T-Mat to send Martian seed pods to selected points on the planet's surface. These emit a fungus that draws oxygen from the surrounding atmosphere, making it lethal to humans but ideal for the Martians themselves.