The freshly awakened and still undressed Robert Jordan hears a horse approaching. This is awkward.
Telling Maria to stay hidden in the robe, he buttons his shirt and grabs his pistol, crouching in the sleeping bag. He aims his pistol at the horseman.
The horseman has on a khaki outfit (with beret), and a red device on his chest. Fascist.
So Robert Jordan shoots him.
It's a direct hit. The newly deceased horseman's body falls off the horse but gets caught in the stirrup, and the horse gallops away dragging it.
Robert Jordan takes the opportunity to put on his pants as the rest of the band pours out of the cave. He tells them the horse must be caught, quickly.
Pilar says that the utterly worthless Rafael was on sentry duty, which explains why the horse got through.
Agustín and Anselmo, at Robert Jordan's urging, run with the machine gun and its accessories to the camp's upper sentry position. They've got to be ready in case more cavalry comes.
Primitivo has caught the horse a little ways up from the cave. Robert Jordan, now fully clothed, goes to examine the body. The horseman was part of a patrol. Which will be looking for him right about now.
Robert Jordan ducks into the cave for a submachine gun and some ammo.
Pablo, who seems to be feeling helpful but really just wants to ride the new horse, takes the horse and says that he will ride it away from the camp to continue the patrolman's tracks. All this after having a bit of wine, of course.
Robert Jordan issues the division of labor for the day: While he, Agustín , Primitivo, and Anselmo keep an eye out for cavalry, Andrés is to saddle and hold the horses, Fernando is to bring Robert Jordan's packs, and Pilar and Maria are to get ready for leaving. He also asks Pilar to strip the dead guy of his papers.
Pablo rides off, and Robert Jordan starts to walk. He pauses. Maria, approaching, says she wants to come, but he says no.
Maria wants him to tell her he loves her.
He says not now.
As Maria leaves, Primitivo asks how she is in bed. Robert Jordan tells Primitivo to watch his mouth.