Then he [Felix] gave orders to the centurion that he should be kept in custody but have some liberty, and that none of his friends should be prevented from attending to his needs. After some days Felix came with his wife Drusilla, who was Jewish, and he sent for Paul and heard him speak about faith in Christ Jesus. And as he reasoned about righteousness and self-control and the coming judgment, Felix was alarmed and said, "Go away for the present. When I get an opportunity I will summon you."
I wonder which aspect alarmed Felix enough to send Paul away. Of course, the next verse tells us that he was hoping to get a payoff from Paul.