The Vanguard

2 aliens are caught because they are considered a vanguard of an alien invasion by their human captors, they are a vanguard but from where.

"We know what you are," said a man in a lab coat to a glowing man.

"Ok then tell me," replied the glowing man in the same language.

"You are a Ufonaught," said the lab coat.

"I am a what?" asked the glowing man laughing.

"An alien to Earth," said the lab coat gruffly.

"Alien," said the laughing glowing man.

"What's so funny?" asked the Scientist shortly.