Booker writes that, in this stage, the characters are in a state "which lays them open to a shattering new experience." It's clear that here, that experience is to grow young again. The "other world" is the world of youth, or second youth, in this case.
Each of Heidegger's four guests revels in their newly given youth. The Widow admires her looks, Mr. Gascoigne shouts about politics, Colonel Killigrew belts drinking songs from the top of his lungs, and Mr. Medbourne seems to think he's on Wall Street again. Everything is great! Surely nothing can go wrong from here.
The three men begin fighting over who gets to dance with the now smoking hot Widow Wycherly. Things quickly get out of hand.
Sure…it's all fun and games until someone loses an eye – or, in this case, shatters a rather lovely vase full of the elixir of life (or possibly just booze, depending on your interpretation).
Booker says of this stage: "At this point the real question posed by the whole adventure is: how much have they learned or gained from their experience? Have they been fundamentally changed, or was it all 'just a dream'?" That is indeed a central question in "Dr. Heidegger's Experiment," and one that we address in "What's Up with the Ending?"