Each time the Giant snores, when he snores in, his goat herd and Finn are drawn almost into his mouth - and when he snores out it is in reverse. But when Finn bites his thumb he knows what to do from the supernatural knowledge, and he takes his sword and shoves it in the Giant's single eye, blinding him.
But this Giant isn't giving in, and so he sits up and roars that Finn is as good as dead. He sits down in the doorway of the cave but Finn escapes by clinging under a goat as they are let out.
The Giant realizes Finn is out but instead of admitting defeat he places a tracking device on him by giving him a ring as a gift. This ring, once on Finn's finger, calls out to the Giant where Finn is. Finn has to run away repeatedly from the Giant's pursuit, where he hopes to crush Finn dead. But Finn's companion, the dog Bran runs up to him and asks him to bite his thumb to get the knowledge and once he does so, he cuts off his finger with the ring on it. He throws it into a swamp, and the Giant asks where it is. The ring answers, and the Giant throws himself into the swamp, and remains stuck there.