Midway through, “Pericles” finds its sea legs, mostly because the action shifts to Pericles’s daughter, Marina, played by the luminous Emily Young. This also signals the play’s move away from struggle and loss and toward redemption and joy, more natural keys for Fiasco, which has always excelled at comedy. The brothel scenes, in which a chaste Marina reforms would-be customers, are sprightly. And the ending, among Shakespeare’s best, is suitably moving. But the chief delight here, as in any Fiasco show, is watching the actors work with such fluency and in such communion, supporting and enjoying one another’s work. That’s not quite a miracle, but it’s reason enough to set sail.