The battle with the Chained was originally when Quinn and Peter's return had been broadcasted. At the time no one was quite aware that it was them that had appeared and they just assumed that it was a new group. They had assumed it perhaps was a guardian that worked for the Red Vampire's Laxmus.
Originally, the battle had ended and it had done so with the presumed death of Russ. There were many that thought he might have just gone missing, but according to Quinn himself, he stated that Russ was indeed dead.
However, it was only later that Quinn himself would find out that Russ was alive, which was why seeing Russ now in front of them, had come to a complete surprise to Shiro.
Geo could feel the tension between the two in the room, they were trying to kill each other with their stares, which is why he decided to step in the middle of the two.
"I assume you two aren't good friends then, are these humans enemies of yours?" Geo asked.