A neo-Nazi couple recently out of prison may soon be back behind bars after they allegedly blabbed to an undercover informant last month that they planned to sabotage power stations in Maryland.

Brandon Russell, 27, and his girlfriend Sarah Clendaniel, 34, are accused of plotting to shoot up five substations that serve the Baltimore area—an attack Clendaniel told a federal informant would “completely destroy Baltimore,” said Erek L. Barron, U.S. Attorney for the District of Maryland.

Russell and Clendaniel are facing up to 20 years in prison for the foiled attack plan. Their first court appearance will be on Monday in Baltimore federal court.

Russell, a neo-Nazi leader who founded the far-right group Atomwaffen, had been jailed in 2018 for keeping lethal bomb-making materials in his apartment. Atomwaffen has been known to threaten journalists, African American churches and Jewish organizations. Clendaniel was locked up in a different prison for a spate of convenience store robberies where she wielded a machete and demanded cash and cigarettes.

Despite being in separate facilities, court filings summarized by Barron in a press conference Monday revealed that Russell and Clendaniel hit it off while incarcerated and allegedly teamed up to attack power stations once out.

Thomas Sobocinski, the lead agent at the FBI’s Baltimore field office, called the couple “racially or ethnically motivated extremists.”

Part of the couple’s devious plan was to hit the power stations after a winter storm “when most people are using max electricity,” prosecutors said in a criminal complaint, the Washington Post reported. Sobocinski said that Clendaniel told an informant their goals were to “lay this city to waste,” referencing Baltimore.

“The accused were not just talking, but taking steps to fulfill their threats and further their extremist goals,” Sobocinski said.