New Plan

Jean appeared in the room a few seconds after Grey left. The second person to get to the vault was the expert who was at the garden. 

He was taken aback when he saw the trapping array intact, it wasn't even destroyed which meant the thief should be in the vault. Unfortunately for him, when he walked in, all he saw was Jean in his sleeping robe. 

"Where's the thief?" He asked after looking around. 

"Whoever came to steal the essence stones has escaped. But given how quickly they escaped with that many stones, I'm starting to have doubts if it isn't someone from the family," Jean said. 

Each family all had their problems, so it was normal for Jean to suspect someone in the family. There's no way someone would be able to take that many essence stones in such a short time.