Sal’s Gram and Gramps Hiddle are an unpredictable pair. They have a peculiar line of reasoning for decision-making that doesn’t always make sense to others. In Chapter 5, Sal tells about a trip to Washington, D.C., when her grandparents “borrowed” the tires off a senator’s car, their own tires being flat (Sal explains that this is something that one could do in Bybanks, but not in the nation’s capital). In the same chapter, Gramps tries to help a woman who is having car trouble, only ending up tearing out all the hoses from her engine.
In Chapter 15, Sal and her grandparents stop by the river for a quick swim. As they are approached by a suspicious boy, who claims that they are on private property, a poisonous snake bites Gram. Though they are able to get her to the hospital for help, she is never quite the same after that.
In Chapter 41, when Gram is in the hospital following a stroke, Gramps gives Sal the keys to the car, even though she is underage and unlicensed. She reaches her destination, but she encounters the sheriff. Though he helps her with the task of finding the spot where her mother’s bus went off the road, he takes her back to town to Gramps, but due to Gram's death, he does not serve Gramps with any consequences for allowing Sal to drive.
Gram and Gramps find themselves in trouble mainly through their good intentions and unfamiliarity with the “wider” world. Though Sal’s father says that he should have just called the police as soon as they left the driveway, they never intentionally seek to cause trouble. Trouble finds them anyway, but their innocence usually keeps them out of serious mischief.