Uh, not so fast. Her parents write back saying that there's some bad news: thinking they were in the clear, they already spent one of those four guineas that the master had given Pamela.
So, now they've got to scrape together some money to return to Mr. B, since they don't feel right accepting it now.
There's also some talk about logistics for getting Pamela safely home, and that wraps up Letter 17.