Writer-director Don Bluth was the main alternative to Disney in animated feature films of the 1980s. Frustrated with what he saw as Disney's lackluster products and slow pace, Bluth took a group of animators with him to establish an independent company. Their first effort was The Secret of NIMH, about a mouse who has lost her husband and hooks up with a pack of super-intelligent rats who've escaped from an experimental laboratory. The smart rodents help her and her family survive a perilous journey. Though it breaks no new ground technically, the highly professional animation is richly detailed, partially compensating for a plot that sags at times. The success of The Secret of NIMH enabled Bluth to establish his own cartoon-making machine, which, a few years later, would produce such fine family fare as An American Tail and The Land Before Time.