 On the night of the Flu Season Dance at his school, his desire leads him to ask Rick for a love serum, and Rick acquiesces, giving him a serum derived from voles.Upon Morty giving Jessica (who, unbeknownst to Morty, has the flu) the serum, it latches onto the flu virus and goes airborne, spreading through the entire planet in a matter of minutes and causing every person not directly related to Morty to fall in love with him.In an attempt to counteract the DNA used in the original serum, Rick makes an antidote from mantis DNA, but the serum fails, instead causing the world's population to mutate into monstrous mantis-people, all of whom want to eat Morty after mating with him.