Immersive theater is a new trend where there are no seats and no stage. The audience moves through the space like a virtual reality video game. I've experienced a film noir-themed Macbeth and a fictitious elementary school reunion set in a real East Village apartment, but my favorite immersive show thus far is Then She Fell -- a retelling of Alice in Wonderland. Tom Pearson and Marissa Nielsen-Pincus of Third Rail Projects explain how the show reflects Lewis Carroll's own duality and the mystery behind his relationship with the real Alice.