Since War and Peace isn't really a novel, and since there are so many different genres mashed together into this work, we don't actually get a nice neat Seven Basic Plots deal. So we're just choosing one of the narrative threads to work in this section – the struggle against the French army in general, and Napoleon in particular.
If the monster is Napoleon, the anticipation stage is pretty clear. By the time he starts massing troops on the border, Napoleon is world-renowned as the most awesome military mastermind in all of history. Still, there's a chance a peace treaty will be reached with Emperor Alexander, so maybe the threat can be avoided. But in general – yikes, Napoleon. No one wants Russia to be all Frenchified. (Oh wait, the aristocracy can barely even speak Russian.)
A bunch of heroes travel to defeat the monster in various ways. On the macro scale, we've got General Kutuzov, an unlikely bottom draft to lead the Russian army. Meanwhile, on the micro level, we have Andrei, Nikolai, Denisov, Dolokhov, and Boris, all signing up to go into the army. And finally, on the crazy level, we have Pierre slowly convincing himself that he's supposed to go assassinate Napoleon. Go team!
After some jockeying for position, the armies clash at Borodino. Lots of people die, and it's hard to know who's the winner. On the one hand, the Russians clearly did massive damage, but on the other hand Kutuzov orders the army to retreat and the French are poised to take over Moscow.
The French actually take over Moscow. Argh! Also, they capture Pierre, fatally wound Andrei, force everyone to evacuate the city, and fail to prevent Moscow from being burned down.
Pierre is rescued by Denisov and Dolokhov (yay). Andrei dies (boo). The French army dissolves and retreats all the way back to Paris, with massive casualties and a broken spirit (yay). Napoleon is imprisoned, only to soon return again to mount a new campaign, this time again England (boo). But we know that he will be defeated again by Nelson at Waterloo (yay).