They soon learned that Hirsch has stowed away in the lighter in a desperate attempt to get away from Sulaco and is hysterical.
This discovery definitely presents a bit of a complication, since they are trying to get away from shore as quickly and quietly as possible. They know that the steamer from Esmeralda will be arriving soon—and that the soldiers on board will definitely be interested in stealing that silver—so keeping their presence on the DL is key.
They aren't sure what to do with Hirsch, but the moment for killing him (which both Nostromo and Martin considered) has passed. Good for morality, bad for… everything else.
Since they can't, you know, turn on any lights or make any considerable noise whatsoever, they are kind of hampered in the navigation department. Also, there is no wind. These guys just can't catch a break, it seems.
Nostromo decides that he will try to get them over to the Isabels, a group of small islands off the coast, so they can hide the boat from view before daybreak. He does not want to just be floating out there, visible to all, when the sun comes up.
However, before they can execute that plan, they hear the dreaded steamer approaching.
The steamer stops very close to them (eep). However, since it is still dark, and Nostromo and Martin are being super quiet, the steamer folks don't know they're there. Yet. Martin and Nostromo keep chatting quietly while waiting for the situation to resolve, discussing what they will do with the treasure if they are discovered and how they would attempt to get away. Sinking their own ship seems to be the best option.
Then the omniscient narration kind of switches over to give us a glimpse of what is happening on the steamer, including Sotillo's thoughts and motivations in heading toward Sulaco. Apparently, he has no idea that the President has escaped, or that Montero is actually on his way to Sulaco as well. Also, he has no idea that folks in Sulaco had been warned he was coming.
We also learn about the various squabbles that are going on on the steamer, some of which lead the engineers to stop the steamer briefly.
When the steamer's captain finally get a brief glimpse of the Isabels, a key orientation point, he knows exactly which direction to go in to get into the harbor. He starts moving the steamer thataways.
The narration switches back here to Nostromo and Martin on the lighter, who hear the steamer on the move and correctly guess where it is headed.
Well, almost correctly—they think that the steamer would pass close to them but avoid hitting . . . well, they are wrong about that. The steamer hits the lighter obliquely, leaving the lighter half-swamped as a result. Uh oh.
The good news is that those aboard the steamer have no idea there had been a collision, since the steamer is so much larger. However, in the wake of the incident, Hirsch starts screaming once again and ends up in the water, where the steamer picks him up. He is questioned, but Sotillo and his men don't really believe anything he had to say, since he seems too freaked out to make sense.
Meanwhile, back on the lighter, Nostromo and Martin pump water out to try to keep her afloat long enough to get her to the Isabels. They succeed, coming ashore and hiding the treasure without being detected.
Then, leaving Martin with the food from the boat and the treasure hidden, Nostromo gets back in the lighter and heads out again, promising to try to return within a couple of days.
Although he has originally been planning to head back to the harbor on the lighter, Nostromo figures that he would get a lot of questions that way and probably end up in prison. So, instead, he sinks the lighter offshore and, at the end of the chapter, intends to swim a mile to an abandoned fort where he can catch a much-needed nap.