The villains in question were running a business at a street faire in Waterdeep. We had pegged their group as suspicious in general, and figured this was some kind of cover to pass on covert messages or meet with other villains that we were tracking. Wanting to get an opportunity to get a good look at them, and stake them out to see who they were meeting, we showed up and spent some time hanging around keeping an eye on their activities. (They had not met us and we had no reason to think they would suspect us of foul play.)

After a couple of hours of not much happening, we started passing shifts around keeping an eye on them, and Konsi went on a walk around the stalls at the faire, where some gnomes from the temple of Gond were making candyfloss with some kind of contraption. Faelys has a massive sweet tooth, and Konsi (who was magically disguised as a gnome so as not to cause concern in the streets of Waterdeep) figured it'd be really cool to learn to make candyfloss, so she asked the gnomes how the machine worked. They refused to tell her, but she was determined to figure it out, so she watched them operate the machine for a while to try and learn what she could about it.

As a part of this investigation, she cast detect magic, to see if the machine was in any way magical (it wasn't, it was purely mechanical) - so, a little despondant, she returned to the group staking out the villains, only to discover that all of them had magical illusion auras - as they were all wearing magical disguise amulets.