How did Buck and the men rescue Thornton from the creek?

The rescue attempt continues when the men now tie a rope around Buck's body and, after one failed attempt, Buck swims out to Thornton successfully, and the dives out quickly from the rock, wrapping both hands around Buck's body amidst the raging current. Hans then pulls the rope tightly against a tree, causing the current to push Buck and John further downstream, but the angle of the rope causes them to merely make a semicircle and land ashore a bit downstream, thanks to that rope. A waterlogged John first checks Buck for injuries and, upon discovering that the dog has three broken ribs, he declares that they will camp there until Buck is completely healed, which the men do.