As the tide starts to turn, Piya spots several dolphins close to shore, twelve miles southeast of Garjontola. She wonders if this is a different pod of dolphins than the ones she observed at Garjontola, but she feels that something isn't right. When they get closer, she notices the calf's body on the mud and reasons that the dolphins don't want to leave until the water reclaims the body. She and Fokir climb out of the boat and she takes measurements and samples of the calf's body before heaving it into the water. Fokir mimes that the calf was probably hit by a Forest Department boat. Fokir gestures that he sees sights like this often.
It's especially chilling that the calf was probably hit by a Forest Department boat, as that means that the very people installed in the Sundarbans to protect wildlife are actively doing the exact opposite. This in turn supports the novel's suggestion that entities like the Forest Department are misguided attempts at conservation, and it's better to work with fishermen like Fokir, whose boat cannot hurt a dolphin without a motor.
Horen has had enough of the search after three hours and insists they need to turn back to conserve fuel. Kanai asks Horen what will happen when the cyclone hits and asks about the cyclone Horen lived through in 1970. Horen says he was out at sea in his uncle's boat, and the storm caught them by surprise. They had no compass, though the wind was so strong they wouldn't have been able to steer effectively even with one. Finally, the boat drifted towards land and hit a tree trunk on the flooded shore. Horen pulled himself and his uncle into the tree and tied them to it with their gamchhas to ride out the storm.
When Horen and his uncle use a gamchha again to keep themselves from blowing away, it again reinforces the gamchhas' symbolism as items that connect people. The cyclone that Horen talks about reinforces that nature can strike with absolutely no notice, and the results can be devastating. Further, notice that Horen and his uncle weren't even able to control their boat; nature was the one dominating.
In the morning, the sky was clear, but the land was still flooded. There were others in trees, and Horen learned that they'd made land 30 miles away in Bangladesh. They were there for two days and saw the land littered with human and animal corpses. Finally, they snuck back to India. As Horen and Kanai reenter the Garjontola pool, it's clear that Fokir and Piya aren't there.
Horen's account of the cyclone illustrates that the dangerous part of the cyclone isn't necessarily the cyclone itself; it's the fact that the cyclone creates lasting damage. It very clearly has little regard for human life given the bodies Horen observed.