The email began floating around the agency’s top ranks after the EPA’s Inspector General expanded its inquiry into Pruitt’s hiring practices to include the raises, according to the two administration officials. In early April, as first reported by The Atlantic, Pruitt requested hefty salary bumps for Greenwalt and his director of scheduling, Millan Hupp. When the White House refused to sign off on the raises—$56,765 and $28,130, respectively—Pruitt used an obscure hiring authority under the Safe Drinking Water Act to grant them anyway. The provision, which allows the EPA’s administrator to appoint up to 30 staffers without White House or congressional approval, was intended to help the agency bring on experts and staff up especially-stressed offices. Greenwalt and Hupp’s raises went into effect on April 1, according to HR documents obtained by The Atlantic.

Now, the agency’s IG is probing whether Pruitt abused that hiring authority. On Wednesday, Pruitt was pressed by Fox News’s Ed Henry to respond to The Atlantic’s report, but denied any knowledge of the episode. “You didn’t know they got these pay raises?” Henry asked. “I didn’t know they got the pay raises until yesterday,” Pruitt responded.

“My jaw dropped when he said that,” said the first administration official. The perception that Pruitt had gone on TV and lied, the official said, was what really scared people inside the agency.

After the interview, top aides, including Jackson, began corralling files that appeared to contradict Pruitt’s statements. The two administration officials described it as a way of “getting ahead” of the IG’s investigation. Greenwalt’s email, however, has proved the most troubling, according to both administration officials. “It’s an ‘oh, shit’ moment that they’re trying to figure out before the IG finds the email,” said one. “Because it’ll be damn near impossible to have Sarah explain her way out of it.”

On Monday, two Democratic members of the Senate’s Committee on Environment and Public Works, Tom Carper and Sheldon Whitehouse, sent a letter to Pruitt citing The Atlantic’s previous reporting and the Fox News interview, and asking him to turn over all relevant documents and communications that might illuminate “the degree to which you were aware of, supported, directed or were otherwise involved in the decision to award Sarah Greenwalt and Millan Hupp raises” by April 20.

The scrambling comes as EPA officials are trying to tamp down the seemingly endless set of controversies plaguing the agency. On Monday, The New York Times reported that the government’s top ethics official had sent a letter to the agency urging ethics staffers to take “appropriate actions to address any violations.” The letter specifically addressed Pruitt’s rental of a condo connected to an energy lobbyist for just $50 a night. It also touched on Pruitt’s frequent trips home to Oklahoma on the taxpayers’ dime. Those flights “do raise concerns about whether the administrator is using his public office for personal gain in violation of ethics rules,” wrote David Apol, acting director of the Office of Government Ethics.