H. Beam Piper 
The Cosmic Computer 

Thirty minutes to Litchfield.

Conn Maxwell, at the armor–glass front of the observation deck, watched the landscape rush out of the horizon and vanish beneath the ship, ten thousand feet down. He thought he knew how an hourglass must feel with the sand slowly draining out.

It had been six months to Litchfield when the Mizar lifted out of La Plata Spaceport and he watched Terra dwindle away. It had been two months to Litchfield when he boarded the City of Asgard at the port of the same name on Odin. It had been two hours to Litchfield when the Countess Dorothy rose from the airship dock at Storisende. He had had all that time, and now it was gone, and he was still unprepared for what he must face at home.

Thirty minutes to Litchfield.

The words echoed in his mind as though he had spoken them aloud, and then, realizing that he never addressed himself as sir, he turned. It was the first mate.