What's Going on in Acts 21?

Last time we left off in the Acts, chapter 20, it's a really sorrowful moment for Paul. He is on his way to Jerusalem to bring an offering from all these different Gentile churches. But here in the very beginning of chapter 21, you have disciples in this town of Tyre telling him that he shouldn't go on to Jerusalem. So how do we deal with this apparent contradiction between the Holy Spirit and what apparently is going on here in chapter 21?