One of them was John, who was retreating up the hill.

The others were following him.

Sir George and Sir John Guild had unexpectedly returned from Derby.

They had left their horses with the stable boys and were walking toward the kitchen door when Sir George noticed a man pass from behind the corner of the terrace garden wall and proceed up Bowling Green Hill.

The man of course was John.
Immediately Sir George and Guild, accompanied by a servant who was with them, started in pursuit of the intruder, and a moment afterward Dorothy heard her father's voice and the discharge of the fusil.