Valdeaulin wouldn't knock, so Gaius feels safe in saying, "Enter."

Severa would do it out of vague politeness, and Estinien because he's not a fool -- he's seen the man barge in, but he's taken better care with Gaius, the longer they've known each other. He'd rather not examine that too hard lest he bring up some unpleasant questions and their answers, but he takes it as it is for now.

Clothing has been laid out -- under layers, mostly, to protect against the cold -- but not yet changed into. When it's Estinien that enters, he says, "How fared your search?"