"I promise I won’t," the Long ’Un declared, and so once more Koko stretched his short legs to the utmost in order to keep in step with Jim. Miss Dora Maybury was quite one of the handsomest girls that ever obtained employment--by competitive examination--in the London Post-Office. It was, therefore, not at all surprising that the susceptible Jim Mortimer should have been so affected by her beauty. Dora’s hair was chestnut brown; the dreamy depths of her dark eyes were fringed o’er with long lashes, from beneath whose graceful shadow she gazed upon the world with an expression that was at once distracting and unconsciously coquettish; her lips closed in exquisite lines upon teeth that were as white as you could wish them to be; and the whole form of her face--from forehead to chin--was such as the most censorious judge of a human countenance would not have desired to be other than what it was. Dora was tall, too, and of graceful figure--in brief, she was as comely a maid as you could well behold in a year’s journeying. It sometimes occurs that a girl brought up in luxury finds herself suddenly plunged into genteel poverty. Such was the case with Dora. Not so very long since she had lived in a great house, and ridden in carriages; then Fortune, in a sudden freak of fancy, had turned her back upon her, and, as if by a sweep of a fairy’s wand, the mansion had changed to much humbler quarters in London, and the carriages into penny and halfpenny omnibuses. It was natural that the unusually prepossessing girl behind the counter of the post-office in Milverton Street should attract a good deal of attention. Those who had occasion to send away telegrams pretty often--busy, preoccupied men though most of them were--soon came to notice this particular clerk’s refined voice and manner. She had not been engaged in post-office work long enough to have acquired the slap-dash, curt style of the lady-clerk who has sat at the telegraphic seat of custom for several years; she was still sufficiently of an amateur, indeed, to display some human interest in many of the messages which were handed in to her. Not that a telegraph clerk is supposed to do this; but Dora could not forbear a smile when she was counting the many words of a wire from a love-sick swain to his lady-love, nor could she feel quite indifferent when a telegram bearing the direst ill-news--news of grave illness or even death--passed through her hands. But we do not wish to have it supposed that we are holding up Dora Maybury as an angel of pity--or, indeed, as a perfect character in any sense. When business was slack, and Dora had time to think about herself, a pettish and discontented expression might often have been observed to flit across her pretty face. As a post-office clerk, Dora felt that she was not filling her proper niche in the world--and probably a good many other people thought so too.