Alien Ambassador's species

The Alien Ambassador's Species were a peaceful, advanced, radiation-dependent humanoids that emitted deadly levels of radiation and could channel blasts of energy from their hands. Completely alien in many ways, they communicated via radio communication impulses rather than speech and were not susceptible to G-force. They are were also impervious to bullets thanks to some kind of forcefield.

This species utilised enormous, half-mile wide, discoid-shaped spacecraft and could create different environments inside. They also possessed mind conditioning technology and weapons capable of destroying worlds.

Alien ambassadors visited Earth some time after making contact with a Human exploration mission on Mars, where one astronaut was accidentally killed. The surviving astronaut from that mission, by then a high-ranking if unhinged British army officer, kidnapped the ambassadors. After forcing them to carry out a series of raids and assassinations his organisation planned to expose their existence to the world, thus stirring up public opinion and forcing world governments to launch a nuclear strike against their spacecraft. (DW: The Ambassadors of Death)