She laughed nervously.

“Well, I’m glad of that; and we’ll not stand here discussing the matter.  Do you know who I am?”

“Divil a thought have Oi.”

“You were expecting to meet Mr. Enright, weren’t you?  That was what Bill Lacy told you.  He was to explain to you just what you were to do.”

Brennan mumbled something indistinctly, now thoroughly aroused to the situation.

“Well, Mr. Enright couldn’t come, and Lacy is over across the creek yet, hunting down Ned Beaton’s murderer.  I am Miss La Rue,” she hurried on, almost breathlessly, “and I’ve brought you Lacy’s note, which you are to give to that Mexican—­Pasqual Mendez.  You understand?  You are to give it to him, and no one else.  Lacy said you could kill your horse, if necessary, but the note must be there by daylight to-morrow.  Here—­take it.”

Brennan thrust it into an inner pocket, and cleared his throat.  There was no small risk in asking questions, yet, unless he learned more, this information might prove utterly useless.  The note to Mendez meant little until he discovered where that bandit was to be found.  He felt his flesh prickle in the intensity of his suppressed excitement.

“Shure now, miss,” he said insinuatingly.  “Mr. Lacy must hev’ sint more insthructions ’long with ye then them.  All ther word thet iver come ter me wus ter saddle oop, ride down here an’ mate this man Enright.  I don’t aven know fer shure whar ol’ Mendez is—­likely ’nough he be in Mexico.”

“In Mexico!” indignantly.  “Of course not.  Lacy said you knew the trail.  It’s a place they call ’Sunken Valley’—­out there somewhere,” and Brennan could barely distinguish the movement of her arm desert-ward.  “It’s across that sand flat.”

“Shoshone?”

“Yes; I couldn’t remember the name.  That’s all I know about it, only Lacy said you’d been there before.”

“Shure, miss,” assured the marshal softly, clearly realising that he had already gone the limit, and that any further questioning must lead inevitably to trouble.  “If it is Sunken Valley I’m ter ride ter, thet’s aisy.”

“Then it’s good night.”

She vanished up the side-trail, as though the wind had blown away a shadow.  Except for the slight rustling of dried leaves under her feet, the two men, staring blindly through the darkness, could not have told the direction in which she had gone.  Then all was silence, the mystery of night.  Brennan gathered up his reins, straightening his body in the saddle.  He glanced back toward the dim shade of his companion, chuckling.

“Some bit of luck that, Jim.”

“Doesn’t seem to me we know much more than we did before,” Westcott answered gloomily.  “Only that this chap Mendez is at a place called Sunken Valley.  I never heard of it; did you?”

“No; I reckon it’s no spot the law has ever had any use for.  I’ve supposed all along them Mexican cattle thieves had a hidden corral somewhar in this country; but nobody has ever found it yet.  Right now, thanks to this Miss La Rue, I’ve got a hunch that we’re goin’ to make the discovery, and put Bill Lacy and ol’ Mendez out of business.  But there’s no sense of our gassin’ here.  We got a right smart bit o’ ridin’ to do afore daylight.”