at the camp, claudia tells agrippa sextus is really the son of pompeius, who was killed in battle by caesar. she explains he plans to assassinate octavianus (caesar's only surviving blood relative) in order to gain support for his conquest of rome. meanwhile, octavianus finds a note in caesar's handwriting speculating as to the worthiness of possible successors, and learns that antonius was not his chosen heir. at the camp, sextus abruptly disappears along with a number of gladiators, and claudia learns he is working for iris and charmian. in rome, sextus confronts octavianus, and is about to kill him when claudia intervenes. octavianus flees, and witnesses decius stabbing marcus. a dying marcus tells octavianus that decius is the "other brutus." maecenas then has octavianus arrested.