For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Dr. Heidegger invites his guests over to his creepy study and tells them about the elixir he has procured.
Act II
The guests drink the potion and act like fools; they shatter the vase.
Act III
The guests grow older again. Heidegger evaluates the results of his experiment and draws his conclusion, while his guests have clearly learned nothing at all.