Disclaimers: Harry Potter is owned by J.K. Rowling. The YouTube vid is owned by the Scottish musical group, Texas.
This story is the result of Snapewidow showing me a YouTube vid in our chatroom here at P&S. The vid is a music video where Alan Rickman makes an appearance. I highly recommend you type in "Hypnotic Tango Dancer - ALAN RICKMAN" into the YouTube search and watch before reading.
Just to warn you before you hopefully enjoy, though, I tried to go for the Mugglelized (probably not a word, but English is full of creative words) versions of Snape, Harry, and Sinistra in the middle of the story partly to stick with the YouTube video. So think of that part as Snape, Sinistra, and Harry dressing up as Muggles for Halloween. :D Okay, enjoy. ;D