Task: Question Generation
Input (English): Passage: Home from the Civil War, where he fought for the Union army, John Willoughby now lives in the western town of Kittreck Wells with wife Nora and their 7-year-old son, Petey. An appeal for help from Marshal Russell comes when a band of former Confederate soldiers are seen pulling a robbery in a neighboring town. John, who hates all rebels, agrees to go, against his wife's wishes that all his fighting must end.
Meanwhile, the Rebels, Bedloe Mason and his sons Gray, Wesley, Cain and Frank, decide to ride into Kittreck Wells to replenish their dwindling water supply. Bedloe sends Gray, Frank and Wesley into town while he and Cain await their return. Petey Willoughby, who shares his father's dislike of rebels, aims and fires a cap pistol at them. Startled by the sound, Wesley Mason shoots and kills the boy. As the brothers mount their horses and gallop out of town, Gray, not having been witnessing the shooting, hesitates, then catches up to the others. 
When they reach Bedloe and Cain, Gray, angered by his brother's recklessness, appeals to his father and brothers that Wesley has to go back to face the consequences. Wesley is dead-set against this and the others take his side. Gray rides off alone to learn the fate of the boy, but Wesley ambushes his brother by throwing a knife into his back. After strapping his brother's unconscious body onto his horse, Wesley sets the animal loose. He then returns to camp and reports that Gray refused to listen to reason, but will meet the family at Oak Fork in three days. That night, John finds the wandering horse bearing Gray's body and takes him home.
Wesley lies to his father that Gray will meet them in the next town. Gray's horse wanders into town, where John and Nora remove the wounded man from the saddle and take him into their home. John is still determined to learn who killed the child, and an eyewitness accuses Gray of being one of the gang. Nora has to stop her husband from attacking Gray with an axe.
Output (English): What are the names of the rebels who Petey aims and fires a cap pistol at?