Though frequently excluded from the Shakespeare canon, The Two Noble Kinsmen cannot be denied its place in the Shakespearean penumbra. True, much of the play came from the fluent, potboiling pen of John Fletcher, Shakespeare’s junior colleague. Still, the stamp of the master is for long stretches very apparent. The plot was derived from “The Knight’s Tale,” the most stilted of Chaucer’s Canterbury sequence: a pair of boon companions, both warriors, fall in love with the same woman, who refuses to choose between them. The outline has the deliberate storybook artificiality one associates with Pericles, Gymbeline, The Winter’s Tale, and the sublime Tempest. And as in those so-called romances from the twilight of the playwright’s career, the outline is filled in with thought of bristling complexity and language of dazzling splendor. The three principals’ great prayers at the altars of Mars, Venus, and Diana before the climactic duel are as solemn in their music and as strange in their imagery as any passage in the collected works. Nevertheless, it is the brave company that takes up the Kinsmen challenge. The Oregon Shakespeare Festival (503-482-4331), in Ashland, did so last month, and continues through October 8. —A. B.