Zhang carried Lilith's clone's body with him, straight to the Royal Castle of the Wolves. Since he was already allowed entry, he wasn't questioned by the Guards. He was just too close to the King, after all.
The real Lilith also walked right beside Zhang, using her invisibility spell. As far as her scent was concerned, even though it was sensed, the Werewolves didn't focus much on it since they believed it was coming from the unconscious girl.
There were two scents, but since they both were identical, no one knew about the second person who managed to infiltrate.
As soon as the real Lilith entered the castle, she separated from Zhang, leaving the responsibility of keeping Zhang distracted on her clone as she went searching for Atlan to find out where he was.
****
Current time~
"I had some help."
Lilith vaguely told Lancaster in response to his question about how she gained an entry here.