The fastenings on every door and every window were intact.
The most plausible theory of the murder was, that some burglar, or burglars, attracted and tempted by the rumor of almost fabulous treasure then in the castle in the form of wedding offerings to the bride, had gained access to the building, and penetrated to the upper chambers, where, finding the banker still up and awake, they had killed him by one fell blow, to prevent discovery.
True, the priceless wedding presents had not been disturbed.

They still blazed in their open caskets upon the drawing-room table--a splendid spectacle.

But then they had been guarded all through the night by two faithful men-servants armed with revolvers and seated at the table under a lighted chandelier.

It was supposed that the robbers, seeing this lighted and guarded room, had crept past it and mounted to the banker's chamber to pursue their nefarious purpose there; that simple robbery was their first intention, but being seen by the watchful banker, they had instantly killed him to prevent his giving the alarm.
For no alarm had been given! Every inmate of the house who was examined testified to having passed a quiet night, undisturbed by any noise.
The hall porter and footmen whose duty it was to see to the closing of the castle at night, and the opening of it in the morning, testified to having fastened every door at eleven o'clock on the previous night, and to having found them still fastened at six in the morning.
How, then, did the murderers and robbers gain access to the house, since there was no sign of a broken lock or bolt to be seen anywhere, except in the safe in the banker's room.
Suspicion seemed to point to some inmate of the castle, who must have let the miscreants in.
Yes, but what inmate?
No member of the small family, of course; no visitor, certainly; no servant, probably! Yet, for want of another subject, suspicion fell upon Peters, the valet.

He was always the last to see his master at night, and the first to see him in the morning.