The apocalypse never came, of course, so the signs of it healed themselves in one way or another. For example, one mother cat decided not to reject her litter of snakes, and raised them all to adulthood. For months they followed her around, chasing after each other's tails and begging for saucers of milk with their best approximation of a plaintive mew, happily ignorant of their true nature.
Years later, one struck up a friendship with a black and white kitten, and was devastated when she was killed by...wait. That girl was the Key! Why didn't anyone else get it?