Benjamin rushed back to Amber City that very night.
After communicating via the magic tool, he and the rest of the mages exited the city and met in the wastelands outside the city to exchange information.
Of course, we say "exchange information", but in reality, this event was mainly for Benjamin to share the information that he had gathered with everybody. The mages had mad great efforts to gather information in Amber City, but the Church had mostly kept to themselves throughout the period, resulting in them making little to no progress.
It was fortunate that Benjamin had met the King, or they would just be walking around in circles.
"… so that is the present situation in Carretas. But, don’t worry too much. We have obtained the support of a highly-influential person. As long as we’re cautious, the Church won’t have anything on us."