The 29th was one of the coldest of nights as the clock ticked away past midnight unto the 30th. In Metropolis, Superman got an alert on an attack at the local cemetery. When he arrived, he saw many graves dugout and a headless undertaker.
"You've got to be kidding," Superman said to himself.
"What? What is it?" Lois asked in his ear piece.
"Zombies," Superman said as he watched one of them crawl out of a grave.
Out in National City, Superman found Kara at her apartment as he woke her up.
"Kal-El," she paused in surprise, "what are you doing here?"
As she sat up in her bed, Clark filled her in on what happened in Metropolis and kindly asked for her help.
Kara called her sister, Alex, to let her know they were needed in Metropolis before she and Clark sped off to Metropolis to find out more.
At Superman's Metropolis base, Brainiac-5 arrived with Alex as they helped Superman and Supergirl figure out what caused the zombies to form.
"There appears to be a leak across the roots of the cemetery grounds," Brainiac spoke.
"Yeah, that's water," Alex noted.
"No, there appears to be an element in the water."
"Hydrogen?"
"No, something else."
Brainiac-5 brought up the chemical element on the screen and Supergirl asked, "What is that?"
"Krypt Ten Tele-Hydroxide," Brainiac informed. "Because of its subatomic particles, it can also be referred to as a type of dark matter. Its elements are dangerous to anyone who is exposed, even those who are dead. It seems when the graves were exposed to this Kryptin chemical it triggered an intense shockwave of dark matter that it created a race of zombies. Anyone who is in immediate contact with them, will be exposed to the Krypt Ten. Its dark matter will transfer. It will spread. There's not much we can do about it. We haven't even found a cure for this dangerous chemical in the 31st century."
"So, is there a way to save the ones who come in contact with those who were immediately exposed to the matter?" Supergirl asked.
"No, there is not," Brainiac bluntly said. "However, if we use your blood, we could begin creating an antidote for those who come in contact with the zombies. The only reason we never found a cure was because we didn't have a source from Krypton. But now I do."
"In that case, let's get started," Alex suggested.
"Kara, since you arrived on Earth much after Kal-El, we're going to have to use your blood since you have stronger Kryptonian DNA," Brainiac suggested.
Supergirl stayed as Superman decided to get help from some friends of theirs in Gotham City and on Prime Earth.
After travelling across the Multiverse, Superman returned with some of Team Flash and Arrow along with Batwoman from Gotham City.
"What are we up against?" Flash asked.
"Zombies," Superman responded.
Flash laughed, "That's funny. Seriously, what are we up against?"
"Zombies."
"Oh, okay you weren't kidding."
Cisco laughed, "Okay, I'm out."
