Critic's Pick-- But “Liberation,” which opened on Thursday at the Laura Pels Theater, is neither satire nor agitprop. As directed with cool patience by Whitney White, the better to let its climax sear, and with a cast led by Susannah Flood and Betsy Aidem each at the top of her form, it is gripping and funny and formally daring. In a trick worthy of Escher, and befitting the complexity of the material, it nearly eats the box of its own containment, just as its characters, lacking other emotional sustenance, eat at theirs.