That was why he had borrowed the hundred dollars from me, and had written to his brokers to sell the bonds.

It was Jeff who was sitting beside Radnor the night they drove across the lawn.

But unknown to Rad, Jeff had found his way back and had robbed the safe, and Rad suspecting it, had refused to make an investigation.
During the eleven days that intervened between the robbery and the murder Jeff had still been hiding in the vicinity--possibly in the neighborhood of Luray, certainly no longer in the cabins, for he had no desire to meet his brother.
But on the day of the picnic they had met and quarreled.

Rad had charged him with the robbery and they had parted in a high state of anger.

This would explain Rad's actions in the hotel, his white face later when I found him in the summer house.