On Thursday, Oct. 31 children and families are encouraged to dress in their spookiest costumes to enjoy free candy and fun at Potomac Mills. From 5 p.m. to 7 p.m., the mall will offer trick-or-treating at participating retailers, marked with a pumpkin sticker in their windows. Guests will also get to snap photos with Halloween characters roaming the mall and visit the photo station in Grand Court (near TJ Maxx) for more fun photo opportunities.