From the doorway William watched her flying fingers with fond pride, and it was very reluctantly that he acceded to Pete's request to go down-stairs for a moment to settle a vexed question concerning the table decorations.
Billy, left alone, still played, but with a difference.

The tripping notes slowed into a weird melody that rose and fell and lost itself in the exquisite harmony that had been born of the crashing chords.

Billy was improvising now, and into her music had crept something of her old-time longing when she had come to that house a lonely, orphan girl, in search of a home.

On and on she played; then with a discordant note, she suddenly rose from the piano.

She was thinking of Kate, and wondering if, had Kate not "managed" the little room would still be home.
So swiftly did Billy cross to the door that the man on the stairs outside had not time to get quite out of sight.