Ever since the day after the tragedy, Emery had been searching for an answer. He had heard the details about the events that transpired in Golden City's prison from his senior Fuxi.
Hence he knew that although they managed to stop the jailbreak from happening and captured the Tiger half-blood intruders, the latter managed to teleport away.
At the time of recall, along with Chumo, the intruders and prisoners were teleported at the same time; these included Magus Cassian, Gorro, Lord Esbern, and also Annara.
From the investigation, it was confirmed that the incidents that had taken place before the tragedy were not just a distraction attempt to hold certain people away from the Magus Academy but also to rescue the infamous Esbern.