Complex sentence: After talking with his captain, they assume that Enna might be burning again--either that, or the burner might be from Tira, because the body was placed where it could be easily seen by the Tiran escort group.
Split into simpler sentences: After talking with his captain, they assume that Enna might be burning again. Either that, or the burner might be from Tira, because the body was placed to be easily seen from the Tiran escort group.