"After the uproar had ceased, Paul called the disciples to himself, embraced them, and departed to go to Macedonia. Now when he had gone over that region and encouraged them with many words, he came to Greece and stayed three months. And when the Jews plotted against him as he was about to sail to Syria, he decided to return through Macedonia. And Sopater of Berea accompanied him to Asia--also Aristarchus and Secundus of the Thessalonians, and Gaius of Derbe, and Timothy, and Tychicus and Trophimus of Asia. These men, going ahead, waited for us at Troas. But we sailed away from Philippi after the days of Unleavened Bread, and in five days joined them at Troas, where we stayed seven days" (Acts 20:1-6).
Although the riot in Ephesus had died down and the Lord's work was going strong, Paul knew it was time for him to move on. He had been in Ephesus for about three years and had no doubt built some strong relationships (cf. Acts 20:31). Before leaving, he met with the disciples, hugged them, and headed for Macedonia. Anywhere Paul traveled he endeavored to edify the Christians, strengthening them in the faith. This he did throughout Macedonia before heading south to Greece (Achaia), where he continued strengthening the church for three months.
It was becoming increasingly difficult for Paul to be safe in any area for an extended period of time. He made many enemies among the unbelieving Jews and also the heathens (like Demetrius, for example). Nevertheless, the persecution Paul continually faced did not stop him from his mission. Paul had planned to sail to Syria but changed his mind due to the plotting of the Jews against him. Although Luke did not record the details of the plot or how Paul learned about it, apparently it was deemed best to change his itinerary.
Paul was joined by several godly men (including Luke himself) on his journey from Greece to Troas. Many of these names are recorded elsewhere in the New Testament, though Timothy's name is the most prominent on the list. It would appear, based on information from Paul's epistles, that these men were joining them for the purpose of going with Paul to Jerusalem. They planned to present the offering for the destitute Jewish Christians that the Gentile congregations had contributed. Taking this gift to the brethren in Jerusalem was a vital thing for Paul, for he hoped it would help cement the unity between the brethren, whether of Jewish or Gentile backgrounds (cf. I Cor. 16:1-4; Rom. 15:25ff; 16:21-23).
Some of the group went ahead of Paul and waited at Troas. Paul's group left Philippi after the Days of Unleavened Bread (mentioned strictly, I believe, for chronological purposes) and joined the others at Troas five days later. Paul's delay in Philippi may be accounted for by the strong affection which he had for the brethren there (and his expectation that he would not see brethren in this area again in the flesh; cf. Acts 20:25). Although the group was in a hurry (cf. 20:16), it is significant to observe that they spent a total of seven days in Troas. It would seem that they wanted to be able to meet with the saints on a Sunday (which they had just missed that week), knowing that a regular assembly would gather at that time.