The senators have gathered and the Emperor arrives escorted by his guards. Constantine realizes he still has deep feelings for his son and warns Massimiano to give a factual deposition. However, during his narration he alleges that Crispo was planning to kill the Emperor. Crispo responds that this is a lie and asks Beroe to tell the facts. She explains that Crispo is innocent and that she is ready to be exiled with him, the truth being that Massimiano and his assassins were ready to kill both father and son. Crispo confirms this explanation, but the father tells the senators to remember what had just been said. Constantine wants to speak to Crispo and all are asked to leave, but although he professes love for the son, when he sees no tears coming from the eyes of Crispo he remains convinced that the son is guilty. Crispo responds that an innocent person has no tears. The senators are summoned back to the hall and deliver a guilty verdict. Constantine realizes that he is about to send his son to the executioner and, trembling, he signs the death warrant.