Of course, discovery was inevitable.  At last O’Neil stumbled in upon her in the midst of her task, and, questioning her, read the truth from her blushes and her incoherent attempts at explanation.

“So!  You’re the one who has been doing this!” he exclaimed, in frank astonishment.  “And I’ve been tipping Benny for his thoughtfulness all this time!  The rascal has made enough to retire rich.”

“He seemed not to understand his duties very well, so I took charge.  But you had no business to catch me!” The flush died from Eliza’s cheeks, and she faced him with thoroughly feminine indignation.

“I can’t let you go on with this,” said Murray. “I ought to be doing something for you.”

But the girl flared up defiantly.  “I love it.  I’ll do it, no matter if you lock me out.  I’m not on the pay-roll, you know, so you have no authority over me—­none at all!”

His eyes roved around the room, and for the first time he fully took in the changes her hands had wrought.

“My dear child, it’s very nice to be spoiled this way and have everything neat and clean, but—­it embarrasses me dreadfully to have you saddled with the sordid work—­”

“It isn’t sordid, and—­what brought you home at this hour, anyhow?” she demanded.

O’Neil’s smile gave place to an anxious frown.

“The ice is rising, and—­”

“Rising?”

“Yes.  Our old enemy Jackson Glacier is causing us trouble again.  That jam of broken ice in front of it is backing up the water—­ there’s more running now, and the ice is lifting.  It’s lifting the false-work with it, pulling the piles out of the river-bottom like splinters out of a sore hand.”

“That’s pretty bad, isn’t it?”

“It certainly is.  It threatens to throw everything out of alignment and prevent us from laying the steel if we don’t check it.”

“Check it!” cried Eliza.  “How can you check a thing like that?”

“Easily enough, if we can spare the hands—­by cutting away the ice where it is frozen to the piles, so that it won’t lift them with it.  The trouble is to get men enough—­you see, the ice is nine feet thick now.  I’ve set every man to work with axes and chisels and steam-points, and I came up to telephone Slater for more help.  We’ll have to work fast, night and day.”

“There’s nobody left in Omar,” Eliza said, quickly.

“I know.  Tom’s going to gather all he can at Cortez and Hope and rush them out here.  Our task is to keep the ice cut away until help arrives.”

“I suppose it’s too late in the season to repair any serious damage?”

“Exactly.  If you care to go back with me you can see what we’re doing.”  As they set off for the bridge site Murray looked down at Eliza, striding man-like beside him, with something of affectionate appreciation in his eyes, and said humbly:  “It was careless of me not to see what you have been doing for me all this time.  My only excuse is that I’ve been driven half mad with other things.  I—­haven’t time to think of myself.”