“Good boy, good boy!” she said to him as he sped along.  But as he began to hasten his pace, it occurred to her that it was only about half an hour’s easy riding to the reservation, and that after leaving there she could easily reach the fort in another half-hour,—­so easily that there was no need of hurrying Tam as she was doing; and she pulled him up with a “Take it easy, Tam dear.”  As she spoke, Tam flung up his head, pricked up his ears, and made a sudden plunge forward.  What was it?  What was the matter?  What had he heard?  He had heard what Molly herself heard in the next instant,—­the beat of a horse’s hoofs.  But the minute it struck upon Molly’s ear she said to herself, “It’s Barney; for that’s old Ranger’s step, I know.”  Ranger was an old troop horse of her father’s that Barney often rode.  But in vain she tried to rein Tam in.  In vain she said to him, “Wait, wait!  It’s Ranger and Barney, Tam!”

The pony snorted, as if in scorn, and held on his way.  What was the matter with him?  He was usually such a wise little fellow, and always knew his friends and his enemies. And he knew them now!  He was wiser than she was, and he scented on the wind something that spurred him on.

But, hark!  What was that whirring, singing sound?  Was that a new signal that Barney was trying?  Was it—­Whirr, s-st!  Down like a shot dropped Tam’s head, and like an arrow he leaped forward, swerving sideways to escape the danger he had scented,—­the danger of a lariat flung by a practised hand.

Oh, Tam, Tam! fly now with all your speed, your mistress understands at last.  She is a frontier-bred girl.  She knows now that it is no friendly person following her, but some one who means mischief; and that mischief she has no doubt is the proposed capture of Tam, who is well known for miles and miles about the country as a wonderful little racer.  Yes, Molly understands at last.  She has seen in the starlight the lariat as it missed Tam’s head, and she knows perfectly well that only Tam’s speed and sure-footedness can save them.  Her heart beats like a trip-hammer; but she keeps a firm hold upon the rein, with a watchful eye for any sudden inequalities of the road, while her ears are strained to catch every sound.  Tam’s leap forward had given him a moment’s advantage, and he keeps it up bravely, his dainty feet almost spurning the ground as he goes on, gaining, gaining, gaining at every step.  In a few minutes more they will be out of the reach of any lariat, then in another minute safe at Wallula’s door.

In a few minutes!  As this thought flashes through Molly’s mind, wh-irr, s-st! cuts the still air again.  Tam drops his head, and plunges forward.