Far ahead to the right the huge bulk of the Tower of London loomed in clumsy power against the deep dark blue of the moonlit sky. Rebecca knew that London Bridge lay not far beyond that landmark, although it was as yet invisible. For London Bridge she was bound, and it seemed to her impatience that the lumbering vessel would never reach that goal. She stood up and strained her eyes through the darkness, trying to see the laboring forms of the rowers in the shadow of the boat's side, but only the creak of the thole-pins and the steady recurrent splash and tinkle from the dripping oars told of their labor. "Air ye goin' as fast as ye can?" she called. "Mr. Droop'll get there fust ef ye ain't real spry." "If spry be active, mistress," said a voice from the darkness aft, "then should you find naught here amiss. Right lusty workers, these, I promise you! Roundly, men, and a shilling each if we do win the race!" "Ay--ay, sir!" came the willing response, and Rebecca, satisfied that they could do no more, seated herself again, to wait as best she might. At length, to her great delight, there arose from the darkness ahead an uneven line of denser black, and at a warning from one of the officers the boat proceeded more cautiously. Rebecca's heart beat high as they passed under one of the low stone arches of the famous bridge and their strokes resounded in ringing echoes from every side. Having passed to the upper side of the bridge, the boat was headed for the south shore, and in a few moments Rebecca saw that they had reached the side of a wooden wharf which stood a little higher than their deck. One of the officers leaped ashore with the end of a rope in his hand, and quickly secured the vessel. As he did so a faint light was seen proceeding toward them, and they heard the steps of a half dozen men advancing on the sounding planks. It was the watch, and the light shone from a primitive lantern with sides of horn scraped thin. "Who goes there?" cried a gruff voice. "The Queen's barge--in the service of her Majesty," was the reply. The watchman who carried the lantern satisfied himself that this account was correct, and then asked if he could be of service. "Tell me, fellow," said he who had landed, "hast seen one pass the bridge to-night astride of two wheels, one before the other, riding post-haste?" There was a long pause as the watchman sought to comprehend this extraordinary question. "Come--come!" cried the officer, who had remained on the boat. "Canst not say yes or no, man?" "Ay, can I, master!" was the reply. "But you had as well ask had I seen a witch riding across the moon on a broomstick. We have no been asleep to dream of flying wheels." "Well--well!" said he who had landed. "Go you now straight and stand at the bridge head. We shall follow anon." The watch moved slowly away and Rebecca was helped ashore by the last speaker.