Red,

 

The 'bubble' that the people disappeared in to is a common effect of a magickal ceremony. If you look at a person that's performed a ritual they often appear to be semi-visible, their skin flushes, and/or they're surrounded in tiny sparkling points of light. Visually they tend to go out of focus if you look directly at them.

 

Performing these sort of rituals raises a tremendous amount of enegy and can draw in an assortment of both positive and negative spirits. I hope you're using something along the lines of the LBRP when you take part in your group's rituals to stay safe.....

 

Blessed Be,

 

--Badger