Lex believed in coincidences, but only as long as they did not involve himself. Weiss had merely begun telling his story, and already he mentioned a place called Avalon. The casual way in which he named it meant to Lex that it was a name Weiss believed that the Innkeeper would be familiar with.
There was also the fact that Weiss was a Celestial, the race that Mary used to belong to. The first apartment building Lex had ever made within the Midnight Inn had been named Avalon by Mary, and Mary was the one who had asked him to talk to Weiss about his home.
In short, it was undeniable that Mary and Avalon were connected. While he listened to Weiss' story, it only took the slightest bit of effort for Lex to look into Avalon. As long as the Midnight Inn or Henali portal had any record of Avalon, he'd be able to know what it was.
