Well, Boris has become quite a political creature.
He has asked to go to Tilsit on the day that Buonaparte is meeting with the Tsar to discuss a peace. June 25th, 1806. This is the day that Rostov picks to come and bring his letter to Boris. It's brilliant how he weaves real history in with his story - it's historical fiction - perhaps the first? Anyhow...
Boris is aware of which way the wind is blowing, and hosts a Francophile Polish count, Zhilinsky, and several French officers in his rooms. Boris comes in, and feels he is interrupting. In fact, he can't help but feel angry at the French. Boris, meanwhile, is truly about his own power. Nikolai can't help but be slightly curt and anti-social.
"Rostov felt ill-humored immediately after he noticed the displeasure on Boris's face, and as always happens with people who are ill-humored, it seemed to him that everyone was looking at him hostilely and he was hampering them all."
Boris asks if he is tired, and leads him into his room. Nikolai feels awkward looking at Boris in the eye, meanwhile, Boris, crossing his legs, and stroking the slender fingers of his right hand with his left, listened to Rostov the way a general listens to the report of a subordinate". It's hard not to pick up on that subtle feminizing of Boris - it's a great detail. Feline. And I think Tolstoy is contrasting politics with the brute force and difficult time that he's shown us through Denisov and Rostov. Either way, it's clear Boris has sold out.
Boris feels like the soveriegn won't do anything anyway, and is harsh in such cases. Nikolai gets snippy with him, and says if he doesn't want to do anything he should just say so, but Boris says he'd like to. Just at that moment he's called away by Zhilinsky, and Nikolai stays in the room listening to the French talk and pacing.
If I were to guess at the future, Rostov will be able to get the letter to the sovereign - there was that whole thing about him swooning in front of him, and that could be a payoff. Probably too Hollywood.
The note about the date says the peace last for five years. So, when we move forward to 1811/12, I'm assuming Boris will have been in a position of power, and Nikolai (maybe married to Sonya we can hope?) will be able to give Boris his comeuppance.
Who knows? I'm clearly not liking Boris. And it's clear he's Anna's son as well. It's great how we see these characters starting one way when we know them superficially and then growing into their true selves. It's actually thrilling.
I'm sure whatever happens will be better than my prediction.
6 months ago