There was something on his mind.

He waited till the company had gone, then consulted with Dave.
They were outside, in the dark, and leant on the dray.

Dad said in a low voice: "He's come a hundred mile to-day, 'n' his horse is dead-beat, 'n' he wants one t' take him t' Back Creek t'morrer 'n' leave this one in his place...Wot d'y' think ?" Dave seemed to think a great deal, for he said nothing.
"Now," continued Dad, "it's me opinion the horse is n't his; it's one he's shook--an' I've an idea." Then he proceeded to instruct Dave in the idea.

A while later he called Joe and drilled him in the idea.
That night, young Donovan stayed at Shingle Hut.

In the morning Dad was very affable.