Q: At the end of the story, why do Andy & Alisha ride away after hearing a familiar voice?
A: As two 13 yr olds, having potentially risked their lives to end the conflict and with not a lot of power or resources at their disposal, they have had enough. It's not to say they no longer care. The 'war' has permanently ended. The pair are not up to being involved in whatever new issue may have appeared. The animals have proved how resourceful they can be and so will be able to find the help they need, should they require outside help. It leaves the way open for someone new to be involved and encourage more people to work in defence of animals, particularly native animals.
Q: Why the use of the Charge of the Light Brigade in the story?
A: More than being simply a good example of the tragedy of war and its accompanying waste, grief and destruction, the Charge of the Light Brigade (25th October 1854), like the Titanic disaster, can be seen as a metaphor for recklessly charging down the wrong path towards destruction without proper prior care and caution. It also demonstrates the danger of the ordinary person not being able to question authority "Theirs not to make reply, Theirs not to reason why, Theirs but to do and die" (From Tennyson's Light Brigade poem). Of the approximately 673 men of the light brigade, approximately 110 were killed and 160 wounded within a very short space of time. It was also a time when British imperialism was beginning to wane but there still existed a haughty belief in its infallibility and superiority. Last, but by no means least, it highlights the needless suffering of animals at the hands of people; an estimated 375 horses were killed in a matter of minutes.