M. Caelius Rufus to Cicero, written from Rome on the fourteenth day before the Kalends of December (18 November) 51 BC (the manuscript dateline: Scr. Romae x iiii K. Dec. a. 703 (51); section 3 gives the same date in the body). The first paragraph records the impact at Rome of the dispatches from C. Cassius and from king Deiotarus that the Parthians have crossed the Euphrates and are pouring into the Roman East — the very news whose despatch from Cicero’s own camp at Cybistra in late September is preserved in Ad Atticum 5.18. Caelius’s private alarm is not for Cicero’s life — the army is too small to fight a real battle, so retreat is expected — but for his reputation, since a Roman proconsul who retreats has to defend the retreat in the city.

The middle paragraphs report the political indecision at Rome that has greeted the news. Names are being floated for an extraordinary command — Pompey, Caesar, the consuls — but no private citizen will be sent by decree. The consuls themselves do not wish to be sent and so refuse to hold the Senate at all, hiding their reluctance under a reputation for civic self-restraint. The standing private suspicion appears: without confirmation from Cicero, the man-on-the-spot, the Roman political class is half-disposed to believe that Cassius has manufactured the whole crisis. Caelius urges Cicero to write to the Senate with careful and cautious accuracy. The closing paragraph turns again to Cicero’s own succession — Caelius cannot promise a successor by the Kalends, but does undertake to prevent a further prorogation, the one commission he had been given on Cicero’s departure (Fam 2.8) and which he has restated in nearly every letter since. The Curio of section 4 is now plainly looked to as the hinge of the new year’s politics.