According to myth, cats have nine lives, and Alexander Catt II (also known as Lexi) has spent his former lives with scientists of medicine throughout history. In these adventures, Lexi witnesses medical breakthroughs and discoveries, and learns the value of hard work and integrity. In Lexi and Lister Defeat Death, Lexi lives with "Dr. Joe" Lister, the Father of Modern Surgery. When mischievous kitten Bart "the Brat" joins the family, Lexi has his paws full. Bart's accident gives Dr. Joe a chance to prove his antiseptic methods. As word of Dr. Joe's life-saving work spreads, he becomes the victim of ridicule, but his perseverance and integrity win over the medical community.