A dog discovers that a friend in need -- is a friend indeed! :)
Probably when they threw the stick, they did not notice that the stick would land dangerously close to the rocks and the water where the strong current could drag their dog away!
In fact, the dog rushes to grab the stick with all the enthusiasm of which he is capable, and, unfortunately, ends up jumping into the water precisely where he should not!
Then, right at the moment when the powerful current is taking him away, the other dog intervenes in the most amazing way!