Chapter 100: How Aren't We Always Expecting an Ambush At This Point
Despite all his commanders telling him, hey, the retreating Wei army is probably in really bad shape now after being stuck in all that rain, Zhuge Liang chooses not to send the army after them. Instead, he predicts that Sima Yi set up an ambush for any pursuers; so he decides, let's give it a couple days, then go after them.
This is where things get a little convoluted. Wei did set an ambush, but since it wasn't triggered, Sima Yi decides to set a second ambush in case Shu was just waiting for the first one to disperse. Which is exactly what Shu did. But as Wei Yan is marching his troops after Wei, he gets a letter from Zhuge Liang saying, actually, don't do that because there's an ambush. The book doesn't draw attention to how Zhuge Liang dropped the ball on this one.
But Wei Yan, still upset over his plan of attack being snubbed in Chapter 92, figures that Zhuge Liang can't be so smart since he let Ma Su lead them to humiliating defeat that one time; and besides, running down a retreating army is the easiest thing ever, which is why it's gone so successfully for everybody these last few chapters. So Shu advances and gets ambushed and loses a bunch of dudes.
When he hears about it, Zhuge Liang shrugs and says, no biggie, I figure Wei Yan is just going to be disobedient sometimes, exactly like I predicted back in Chapter 53, so long as you ignore the fact that he's otherwise been a perfectly capable commander for nearly fifty chapters now. I'm pretty sure he just mentions this to remind the reader of that particular prophecy because it's been so long since it was brought up and most people don't have Skep to constantly point out how inconsistent Zhuge Liang's opinion of Wei Yan is.
In the middle of all this, there's a sub-plot where Sima Yi and another Wei general make a bet as to whether or not Shu will trigger the ambush, and the loser has to wear a dress in camp, but the bet is eventually called off so there's no actual payoff. Except one soldier gets executed for complaining that the only reason he doesn't get to go home after having to camp in the rain for a whole month is because Sima Yi is making frivolous wagers, which is kind of true.
Then the general that Sima Yi made a bet with falls ill. When he hears about this, Zhuge Liang sends him a "get well soon" card. Inside, he includes a letter where he is inspired to eloquently list out all the ways that a commander moves his troops and directs the flow of battle.
And then he writes, "but you can't do any of that and also you work for a traitor, get reeeeckt". Naturally, the guy dies on the spot.
After this, Sima Yi actually writes to Zhuge Liang, asking him to come out so they can do war. No more of this ambush shit, but like, actual let's-smush-our-armies-together war. When they meet up, the two strategists smack-talk each other a bit and eventually agree that the loser of this fight has to retire. Then they bring in their formations.
Zhuge Liang unleashes that weird eight-gate formation that Cao Ren tried against Liu Bei waaaay back in Chapter 36. The difference here is that his men can actually do it correctly. Even though Sima Yi theoretically knows the trick to conquer the formation, the inside is too chaotic, and the officers he sends in get lost and can't make it through. This kind of invalidates a lot of the complaints I made back then, but I still stand by them because now we're admitting the puzzle isn't a puzzle but is really just a plot device to hand tacticians a victory in whatever way is most convenient.
Sima Yi likewise gets mad at this and figures, screw fancy formations, everybody just charge at them I guess. But Zhuge Liang had set up some units to secretly surround Wei before this all began, so they get beaten pretty good again. Sima Yi does not retire as promised.
Sadly, although it looks like Zhuge Liang is scoring some good wins, one of his shipments of grain ends up arriving ten days late because the guy in charge of logistics is a drunk. He goes to execute the guy, but then somebody else says, well, who will transport the grain then?
...I think you can hire a new logistics manager.
But Zhuge Liang is convinced that nobody else could possibly ship the grain, so he just gives the guy a whipping instead. Somehow, he doesn't predict that this makes the guy a bit salty, and the guy ends up sneaking out of the Shu camp to go to Sima Yi. Then, at Sima Yi's suggestion, he goes to Shu's capital and mingles with a eunuch.
Wait, there's eunuchs in the Shu capital? ...Uh oh.
Anyway the guy tells the eunuch, man, I'm pretty sure Zhuge Liang wants to be emperor and is going to oust Liu Shan and usurp the throne. The eunuch, who's a big suck-up, relays this news to Liu Shan himself, who gets a little nervous and tells Zhuge Liang to halt his march and come back to the capital. Alone.