The invitation to “Under the Big Top: Atlas” is intentionally a little cryptic. It’s clear it’s an immersive theater experience. It’s clear it’s $70 for a 30 minute performance. Beyond that, it invites your imagination to wander. There’s mention of 1928, some kind of flood at the circus. A mystery, someone’s disappeared, maybe I can help locate her? And that it’s a partnership with Two Bit Circus. That’s enough for me. I’m intrigued.