the reason why you only chose a text as your material is because you have actually seen and found it appropriate because of the endless amounts of techniques and themes that associate with the imaginitive journey that you identified. although i am quick to criticize, i think it is best if you watched the movie (i mean, which one are you talking about? theres a few...) with a piece of paper and a pen and write down the variuos themes throughout the movie. I havent watched the trilogy myself, only the first one ages ago. there are many things in movies like symbolism (the ring), motifs, editing etc. that show different themes-which is what you need to be looking at