Our markers are art pieces done by Umberto Crenca. On the first sight of these drawings, we found them creepy; however, in a good way that provided us with a lot of inspirations for our design - we decided to create a Halloween themed projects, taking the advantage of the creepiness. When people scan each of the five markers, two buttons will pop up: "trick" and "treat". One can click on "treat" to get a peaceful and pleasant hearts flying out; when one clicks on "trick".. Enjoy and have fun!