But this idea, great and promising as it was, required further fertilisation, and got it from another. The Graal story is (once more, according to authority of the greatest competence, and likely if anything to be biassed the other way) pretty certainly not Welsh in origin, and there is no reason to think that it originally had anything to do with Arthur. Even after it obeyed the strange "suck" of legends towards this centre whirlpool, or Loadstone Rock, of romance, it yielded nothing intimately connected with the Arthurian Legend itself at first, and such connection as succeeded seems pretty certainly[31] to be that of which Percevale is the hero, and an outlier, not an integral part. But either the same genius (as one would fain hope) as that which devised the profane romance of Lancelot and Guinevere, or another, further grafted or inarched the sacred romance of the Graal and its Quest with the already combined love-and-chivalry story. Lancelot, the greatest of knights, and of the true blood of the Graal-guardians, ought to accomplish the mysteries; but he cannot through sin, and that sin is this very love for Guinevere. The Quest, in which (despite warning and indeed previous experience) he takes part, not merely gives occasion for adventures, half-mystical, half-chivalrous, which far exceed in interest the earlier ones, but directly leads to the dispersion and weakening of the Round Table. And so the whole draws together to an end identical in part with that of the Chronicle story, but quite infinitely improved upon it. [Sidenote: Its approximation to the novel proper.]