They've defeated dinosaurs (Knights vs. Dinosaurs, 2018). They've defeated monsters (Knights vs. Monsters, 2019). What could be in store for the knights of Arthur's round table in their final adventure? Suffice it to say, they're feeling uneasy about the disappearance of Morgause and her unpleasant son, Mordred, so when a hulking green knight (as in, Sir Gawain and the Green Knight) rides into Camelot with word that Morgause is visiting Morgan Le Fay in the realm of Faerie, the knights prepare for action--if they can just find a way into the realm. Phelan's conclusion to his off-kilter King Arthur trilogy is as entertaining as any reader could want, with chapter illustrations being the cherry on this medieval cake. Action and comedy are readers' steady companions, while tender moments among the valiant band creep in now and again. Merlin's fated appointment with a tree shakes young Mel in particular, but her apprenticeship with the wizard was not wasted. Phelan brings events satisfyingly full circle, giving Camelot's guardians a merry end.