Help advertising a math class?

I’m going to be teaching a nonstandard math class to 7–10th graders this summer. I want it to be about the business of actually doing math, i.e. thinking about mathematically deep questions and having original mathematical thoughts. There will probably be some specific stuff people have heard of (i.e. infinity) on the syllabus, but I need to write a blurb that gets kids (and their parents) interested in signing up for my class. The summer school also offers standard high school math classes, and those are often well attended. I want to get people who don’t even know, necessarily, that more is possible, but who would like it if they see it. What can I write in my blurb to get a bright student interested in taking my class?