Even though Alan and Davie are moving as quickly as they can across the barren, rocky countryside, Alan still takes the time to knock on every door they pass to let the local people know about the murder. More than half of them have been informed already.
They're in such a rush that Davie isn't really clear on the path they've followed, especially since all the names are given to him in Gaelic. They run through difficult country, some of which Davie has trouble getting across.
They finally find a little hiding place between two large rocks.
Alan laughs a bit at Davie for his reluctance to jump across large rocks near a dangerous waterfall. The word he uses is "gleg," Scots for "quick and alert" (source) – which, he says, Davie was not.
But when Alan sees how embarrassed Davie is over his fear, he immediately takes it all back and says, "to be feared of a thing and yet to do it, is what makes the prettiest kind of man" (20.14). In this context, "pretty" means brave or gallant (source).
Alan then says that he himself has been a "gomeral" (Scots for fool; source). He took the wrong road and he forgot to bring a bottle of water, which they really need.
Alan tells Davie to go to sleep, which he does.
At around nine the next morning, Alan wakes Davie to tell him to shut up, he's snoring.
Alan and Davie look over the edge of the rock they're sheltering behind.
In the valley below, there are a huge number of infantry soldiers from the English military who've come marching in during the early morning.
Alan says he and Davie will be safe behind their rocks if the troops stay in the valley, but if they start climbing up, they'll easily spot Alan and Davie's hiding place. All there is for Alan and Davie to do is to wait for night and hope no one sees them.
The day grows hotter and hotter and the naked rock starts to burn Alan and Davie as they sit waiting for night to fall. What's more, they have no water to drink.
A soldier comes close enough to their rocks to set his hand on the base. He comments, with an actual English accent (the first that Lowlander Davie has ever really heard), that the day is "'ot" – in other words, "hot." Davie remarks on the way that the English seem to drop the letter "h" in their speaking.
As the day grows worse, Davie and Alan both begin to feel ill, and Davie's only comfort is a passage from a psalm: "The moon by night thee shall not smite,/Nor yet the sun by day" (20.35). In other words, God is protection from both the moon and the heat of the sun.
By around two in the afternoon, the heat is so bad that Alan decides they need to move, despite the danger of being seen.
They jump down from the top of the rock to its shaded side and just lie there for an hour or two, potentially in plain sight of any passing English soldier, because they feel too sick to stand.
Finally, Alan and Davie feel well enough to make a run for it.
Since the soldiers have already searched the valley, they seem to be relaxing their guard.
Alan and Davie manage to creep away, though the whole business is pretty stressful: they have to keep stopping and starting to look around them and see if they've been spotted, and the afternoon is so hot and still that the sound of a pebble falling would immediately bring everyone's attention to them.
At around sunset, they come upon something miraculous: a river with banks high enough to hide them, which they can drink from and wash in. After refreshing themselves, they feel about a million times better, and they make dinner out of oatmeal and cold water ("drammach" (20.42)).
At last they set out again under the moon. Alan is so confident that they've lost the English that he starts singing, whistling, and generally Davie.