The Assassins of Rome by Caroline Lawrence

In this book a group of crime solving, Roman kids, are told of a new scheme that has been happening. A group of three murderers are planning to kill the emperor, and they will do anything just to make this goal happening. One of the friends finds out that one of the murderers is related to him! But he doesn't know that until he has traveled to Rome with him. After there friends disappearance to Rome, the other friends hurry along to Rome, to find their friend, and find out who is attempting to kill the Emperor. This is a fairly easy read.
Can be found in ISP library.