Piya wakes in the morning and sits in the boat, listening to the water. She hears a sound like a breathy sigh and realizes they're surrounded by a pod of Gangetic dolphins, though they're not behaving normally. As she watches, Piya thinks about a Swiss cetologist who, in the 1970s, captured two Gangetic dolphins from the Indus River and carefully transported them to Switzerland. There, the scientist realized that the dolphins are sensitive to atmospheric pressure and behave strangely in inclement weather. Piya catches a glimpse of the sky, which has a strange glow, and yells at Fokir that a storm is coming.
When Piya figures out how to read the dolphins using previous knowledge, it again shows that other forms of communication and "reading" are immensely valuable—figuring out now that there's a storm coming may give them a chance to find cover. It's also worth noting that though Fokir certainly can't understand what Piya yelled at him, he'll absolutely understand the meaning, reinforcing again that their ability to communicate isn't predicated on a shared language.
Horen points to a dark spot in the sky and says they can only wait for thirty minutes more or they won't make it back to Lusibari. Kanai protests, but Horen says they'll go down with bhotbhoti if they stay. He motions to the island and says there's no shelter and it'll all flood anyway. He assures Kanai that Fokir knows what to do.
Horen's assurance that Fokir can take care of himself shows that Horen is well aware of Fokir's connection and close relationship with nature, and he sees this relationship as something positive. Kanai, as an outsider, struggles with this as he's seen and is terrified of the violence of the area.