The cast of Brainpeople (Rorschach Theatre). When a woman offers two strangers $20,000 to dine with her for an evening, there’s naturally got to be a catch. But in Jose Rivera’s Brainpeople, being given a thoughtful, intimate staging by Rorschach Theatre Company, none of the cliche scenarios and hypotheticals that may have popped into the mind apply to what’s about to happen to this trio of women from disparate, if equally desperate backgrounds. Our…