Final answer:
No, it is not clear whether Popilus truly knows what Cassius's enterprise is based on the information provided.
Step-by-step explanation:
No, it is not clear whether Popilus truly knows what Cassius's enterprise is based on the information provided. The text excerpts do not specifically mention anything about Popilus having knowledge of Cassius's enterprise. Therefore, without more information, we cannot determine if Popilus knows or not.