The book "Long Shadows" tells about new adversities in the life of Thunder Cats. In the hour of trials, they are once again convinced that their kind and wise leader Ognezvezd is always ready to sacrifice his life for the sake of his comrades. At the same time, the Shadowclan succumbs to Saul's charms, changing their attitude to Military Law, but Hollyleaf, Lionblaze and Sparrow figure out how to save their neighbors from the influence of this strange cat and restore the old order in the forest. However, the most severe trials still await everyone ahead, because the Firestar's grandchildren accidentally discover the secret of their past, which can destroy many lives forever.