There had never been any question of the latter's attitude toward Siward.
Plank began to frequent the house, but never informally.

It is doubtful whether he could have practised informality in that house even at Siward's invitation.

Something of the attitude of a college lower classman for a man in a class above seemed to typify their relations; and that feeling is never entirely eradicated between men, no matter how close their relationship in after-life.
One very bad night Plank came to the house and was admitted by Gumble.

Wands, the second man, stood behind the aged butler; both were apparently frightened.
That something was amiss appeared plainly enough; and Plank, instinctively producing a card, dropped it on a table and turned to go.
It may have been that the old butler recognised the innate delicacy of the motive, or it may have been a sudden confidence born of the necessities of the case, for he asked Plank to see his young master.
And Plank, looking him in the eyes, considered, until his courage began to fail.

Then he went up-stairs.
It was a bad night outside, and it was a bad night for Siward.