Final answer:
In 'Holes' by Louis Sachar, the Warden suspects one of the boys from Camp Green Lake has found a tube, which is a key piece in the mystery surrounding the camp.
Step-by-step explanation:
In the novel Holes by Louis Sachar, the Warden believes that one of the boys at Camp Green Lake found the tube. The Warden's suspicions lead to heightened tension and scrutiny among the campers, as they try to navigate their daily tasks under her watchful eye. The tube in question is later revealed to be of significant importance due to its connection to the history and mystery surrounding the Yelnats family and the treasure.