The light show took the Narix by surprise, one of the marines taking a half-step back in surprise. Carthus examined the animation, not too excited about the idea of the airlock closing behind them, but they wouldn’t get far without it. He slowly reached for the left side of his helmet with two fingers to speak to the dropship crew.
“Gate’s about to close, looks like we’ll get atmosphere. Three to ten Oxygen - Nitrogen if I understand this correctly.”
“SIr, how do we even tell them ‘yes’ or ‘no’? For all we know, what passes for our hand signals might be insults or whatnot to them.”
“Shut it, Katis, and let the Primarch do his job, he’s got an hour to figure it out.”

The soldier raised a good point, but what else was there to try? Carthus raised his left hand to head height, palm forward and moved the hand up and down about 20 centimeters, nodding his head and pointing at the ‘button’ as he did. He than dropped his arm down and reached for the tacpad on his left forearm, switching his visor to its transparent state and waiting for the alien’s reaction. Ho hoped showing his face could break some ice. After all, hiding ones face didn’t exactly say ‘friendly’. Raising his hand to his helmet once more, he contacted the dropship again. “Have everyone in the troop bay take a seat and appear as non-threatening as possible in case they catch a glimpse of you.”

The entire time, every movement the Narix made was about half the speed it normally would, drawing out the entire ordeal. The Primarch hoped they could quickly achieve vocal communication on at least a basic level. He dreaded to think where this would go if the species didn’t communicate vocally.