This is no trick: no fancy chemicals, hidden glow sticks, or trick punch bowls. This is a punch, made from actual ingredients, that freaking glows in the dark! The trick comes from the quinine, the key ingredient in tonic water. The natural akaloids are UV-reactive, meaning they'll glow a creepy blue when exposed to regular black light bulbs, which are easy to find with all those Halloween stores taking over old Borders and Linens and Things.
In order for it to work better, you've gotta use a solid 50% tonic water, which can get pretty bitter, so the Chow team designed to the punch recipe to include lots of sweet and acidic mixers to make the whole thing work.