Really? Does Brutus say that Caesar is going to join the Optimates? That's good news! But where will he find them? Unless he should by chance hang himself.*
But what about Brutus? You say, ‘It is no good.’ What became, then, of that chef-d'oeuvre of yours which I saw in his ‘Parthenon’—I mean the Ahala and Brutus pedigree?* But what is he to do?
That's excellent hearing! ‘Not even has the prime author of the whole black business* a good word to say of our nephew.’ Why, I was beginning to be afraid that even Brutus was fond of him. For that seemed the meaning of the sentence in his letter to me: ‘But I could wish that you had a taste of his conversations with me.’ But, as you say, of this when we meet.
And yet, which do you advise me to do? Am I to hurry to meet him or to stay where I am? The fact is, I am glued to my books, and on the other hand don't want to entertain him here. His father, as I am told, is gone as far as Saxa* to meet him in a high state of exasperation. He went in such an angry frame of mind that I was forced to remonstrate. But then I am much of a weather-cock myself. So we must wait and see. However, please consider your view as to my coming to Rome and the whole situation; if it appears plain to you tomorrow, let me know early in the day.
Read Ad Atticum 13.40 in Latin here | Check the glossary here
Notes from the translator, E.S. Shuckburgh:
Unless he should by chance hang himself—The boni [= the Optimates] are all killed in the several battles of the civil war. Caesar must go to the other world to find them.
his ‘Parthenon’—I mean the Ahala and Brutus pedigree?—The ‘Parthenon’ is a library or other room in the house of Brutus. Thus Atticus had such a room which he called Amaltheium, and Cicero an Academeia, and Augustus one which he called Syracusae (Suet. Aug. 72). Atticus's chef-d'oeuvre was a pedigree [i.e. family tree] of the Iunian family, ‘which he made at the request of Brutus, from its origin to the present day, noting the birth of each man and the offices he had held’ (Nepos, Att. 18). It enumerated among the ancestors Iunius Brutus, the expeller of the Tarquins, and C. Servilius Ahala, who killed Sp. Maelius for an alleged attempt at tyranny (Phil. 2.26). This was one of the ways in which Atticus—who dabbled in ancient history and antiquities—gratified his great friends. Cicero means, ‘if Brutus submits to Caesar, what is the use of his descent from these tyrannicides?’ We may remember how this was used next year by the authors of libels (App. B.C. 2.112).
the prime author of the whole black business—Hirtius, who had apparently induced young Quintus to join Caesar.
His father, as I am told, is gone as far as Saxa—Probably Saxa Rubra, the first stage on the via Flaminia (Phil. 2.77), about ten miles from Rome. Quintus was coming home from Spain by way of Gaul.