Conrad had no doubt: he had been spotted.
Had he unconsciously given off a murderous intent?
Had something betrayed him?
Had he made too much noise?
He believed none of these explanations, and although he would have liked to understand how, he had no time to ask those questions: the calamity stood before him and his pride would not allow him to retreat.
Without switching off his invisibility, he grabbed the walkie-talkie and sent one last message before turning it off:
"I come , 24 minutes."
This would be understood as "I'm in the middle of a fight," and "24" signified his team number (although he was alone, candidates had been given numbers so they could be identified, and since each had a hiding place so Sirius would know where they were).
As soon as the message was sent, Conrad didn't wait for a reply and drew his knife.
("He's spotted me, certainly, but he can't see me.")
Walking slowly, making no sound, he tried to get behind the calamity.