What does Genesis 43:18 mean?

The brothers were scared when they were taken to Joseph’s house. They said, 'It’s because of the money that was put back in our sacks last time. They’re going to attack us, take us as slaves, and seize our donkeys.' Genesis 43:18 - Modern Text Bible

(The brothers are anxious, thinking they’re in trouble for the money that was returned, and fear they’ll be punished or enslaved.)