During the same time that Luka, Callus and his teammate met with Havos, Lucas was in the shop going through a list of relics to visit to complete the new mission.
The mission didn't specify how many relics Lucas needed to explore, but it did emphasize that for the mission to be concluded, he had to master the magi runes. It wouldn't take an Einstein to figure out that the relics Lucas needed to explore were this pertaining to magi runes and the civilisation behind it. As such, Lucas began looking up for such relics.
This would have been difficult since the hyumans didn't even know much about these ruins, but luckily, Lucas knew where Ronny had found the artefact. Using the location, he mapped out the surrounding relics around it and estimated that they would similarly be related to the same civilisation behind the magi runes.
