Small theatres often become so identified with the leader who brings them to life that it’s sometimes difficult to imagine them without their patron saint. “At least half a dozen of the Twin Cities’ best-known, most innovative, highest-quality theaters face the same situation. Penumbra Theatre Company, Mixed Blood Theatre, Park Square Theatre and Illusion Theater all are facing a future without the artistic directors who have poured their lifeblood into them. Their long-term survival depends on figuring out how to transfuse that lifeblood into a new generation of leadership.”