In the meantime, the sled dogs have burst from their nests in order to protect their food. Then, however, all of the team dogs are attacked by the wild dogs and even the team dogs revert to primitive behavior. London tells us that they "fought the wild dogs with a fierceness." Buck is especially excited by the taste of blood after he sinks his teeth into one of the wild dogs. The taste of blood goads him to "greater fierceness." The sled team dogs eventually escape to the wilderness, but are seriously wounded. Some lose an eye, some lose an ear, and all have gaping wounds; eventually, though, they return to the camp site and find that François and Perrault have driven the wild dogs away. Half of the food supply, however, is gone. This key incident shows the wild, untamed fury of the starving animals who contain a fury which indicates the instinctual desire for survival. Furthermore, in the encounter with the wild huskies, Spitz, rather than fight against a common enemy, uses the opportunity to attack Buck — on two different occasions. The first time occurs when Buck is fighting a wild huskie, and Spitz viciously attacks him from the side; the second time occurs when Spitz rushes upon Buck in an attempt to throw Buck in the path of the wild huskies, an event which Buck realizes would have meant certain death. There have now been three encounters between Buck, the dog of the Southland, and Spitz, the opportunistic dog of the Northland.
With the food supplies half gone, and with four hundred miles of wild trail ahead, François and Perrault begin to lead the dogs on a dangerous journey. It takes the sled team six days to cross the thirty miles that make up the "Thirty Mile River" because the ice keeps breaking under them, and they have to stop and build fires to dry out or else they will freeze to death. At one time, the ice breaks and Spitz, the lead dog, falls in, dragging the entire team, except Buck, in with him. During the rescue, which requires most of the day, another day of travel is lost.
