Intergang has a Christmas present for Superman: a virus from Krypton that could destroy the Man of Steel.
Lois tries to avoid spend Christmas with her parents because they always fight but they surprise her by showing up at her apartment uninvited causing chaos. Her father, Sam, also brought with him his new fiancee, a cyborg named Baby Gunderson.
Meanwhile, Mindy Church who is now the new head of Intergang, even though the organisation is shut down and keeps a low profile, plans to kill Superman using a virus from Krypton with the help of scientist Joey Bermuda.
Superman gets sick and Lois asks her father's help. Sam explains that the only cure will be if Superman gets very close to death since that way the virus will die too. The treatment is successful and Superman gets well, just in time to save Lois and his parents' lives.
They suspect Mindy is behind everything but she craftily manages to frame Joey for turning his back on her and escapes.