Campaign Thingy

Your heroes are all called to mansion, where there is a noble’s masquerade party. They bring their best suits and masks and/or other outfits, and take horse carriages to the mansion. They all arrive at the same time, seemingly by coincidence. They talk outside for a second before going inside. They enter the mansion to see lots of nobles and dukes from surrounding lands, dressed all fancy, and the heroes feel very out of place.