Hetty saw him coming, and ran lightly to open the door for him, and as he took his seat beside her at the table, he forgot straightway his whole trouble, and found himself at once in Paradise once more. All through lunch they talked about other things--happy plans for the future, and the small prettinesses that lovers find so perennially delightful; and long before Arthur went away the twitching in his face had altogether ceased to trouble him. Once or twice, indeed, in the course of the afternoon he happened to glance casually at the looking-glass above the drawing-room fireplace (those were the pre-Morrisian days when overmantels as yet were not), and he saw to his great comfort that his face was resting in its usual handsome repose and peacefulness. A bright, earnest, strong face it was, with all the promise of greatness already in it; and so Hetty thought as she looked up at it from the low footstool where she sat by his side, and half whispered into his ear the little timid confidences of early betrothal. Five o'clock tea came all too soon, and then Arthur felt he must really be going and must get home to do a little reading. On his way, he fancied once he saw a street boy start in evident surprise as he approached him, but it might be fancy; and when the street boy stuck his tongue into the corner of his cheek and uttered derisive shouts from a safe distance, Arthur concluded he was only doing after the manner of his kind out of pure gratuitous insolence. He went home to his lodgings and sat down to an hour's work; but after he had read up several pages more of "Stuckey on Gout," he laid down the book in disgust, and took out Helmholtz and Joule instead, indulging himself with a little desultory reading in his favourite study of the higher physics. As he read and read the theory of correlation, the great idea as to the real nature of energy, which had escaped all these learned physicists, and which was then slowly forming itself in his own mind, grew gradually clearer and clearer still before his mental vision. Helmholtz was wrong here, because he had not thoroughly appreciated the disjunctive nature of electric energy; Joule was wrong here, because he had failed to understand the real antithesis between potential and kinetic. He laid down the books, paced up and down the room thoughtfully, and beheld the whole concrete theory of interrelation embodying itself visibly before his very eyes. At last he grew fired with the stupendous grandeur of his own conception, seized a quire of foolscap, and sat down eagerly at the table to give written form to the splendid phantom that was floating before him in so distinct a fashion. He would make a great name, for Hetty's sake; and, when he had made it, his dearest reward would be to know that Hetty was proud of him.