The Rubicon

The episode title, The Rubicon, is derived from the phrase "Crossing the Rubicon", which means an irreversible decision. As for the origins of the phrase, it goes back to Roman custom or law, where it was required when a Roman Governor or General wanted to traverse from the provinces to the Capital Region (Rome proper), he must disband his troops before crossing the Rubicon River. One Governor and General in particular, contravened said law, Julius Caesar, and by doing so he essentially declared war on the Roman Republic. Caesar was reported to have said "alea iacta est" (pronounced A-LAY-A E-ACT-A EST) , which is Latin for the "die is cast" , die as in gaming dice.

It would likely seem suspicious to the Iranians that the first two people that Reza picked to go back with him to Iran would both drop out shortly after being picked, only to have someone who hadn't worked with Reza that long be picked to go to Iran with him.