On May 18, a top aide to Environmental Protection Agency chief Scott Pruitt testified to a congressional committee that she had been tasked with procuring her boss a used mattress from the Trump International Hotel in Washington, D.C. Just days after news of that testimony broke, the aide, Pruitt’s now former director of scheduling Millan Hupp, submitted her resignation.

But even though Hupp was gone from the agency, Pruitt wasn’t done with her.

According to three sources familiar with the conversations, Pruitt was livid over Hupp’s testimony, which he felt had been particularly humiliating. And he personally reached out to allies in the conservative movement, including some at the influential legal group the Federalist Society, to insist that she had lied about, or at least misunderstood, the request for a used Trump mattress. He also stressed that Hupp could not be trusted—the implication being that she should not be hired at their institutions.

It was an aggressive move by a besieged, scandal-prone Cabinet member against a young staffer—one who worked on Pruitt’s attorney general campaign in Oklahoma, followed him to Washington, and by all accounts had been one of his most loyal aides at the EPA.

But it also showed a side of the EPA chief that top advisers say is not always readily apparent to the public. Though Pruitt demands loyalty among those in his inner circle, he has not reciprocated it to his aides, even as they face a legal and public-relations backlash stemming from his conduct at the agency. Sources say he’s actively undermined the reputations of former and current staffers, with campaigns that former senior EPA officials have described as “ratfucking.”

The targets aren’t just ex-schedulers either.

For months, Pruitt and top aides have suspected Kevin Chmielewski, Pruitt’s former deputy chief of staff, of leaking damaging details about the administrator’s travel and spending habits to the press. Sources say Pruitt led the charge to push back against his former senior aide. And he did so by tasking communications aides with leaking damaging information about Chmielewski’s alleged misconduct at EPA, including supposed unannounced vacations and shoddy timecard practices. Chmielewski has accused Pruitt of retaliation, a charge that is now under investigation by the Office of Special Counsel.

Knowledgeable sources also told The Daily Beast that Pruitt instructed staff to pitch “oppo hits” to media outlets on other officials who departed on bad terms or were sidelined. The targets include David Schnare, a former member of Donald Trump’s presidential transition team, and career official John Reeder, who Pruitt would privately call a “communist,” according to two people familiar with Pruitt’s complaints and thinking.

Pruitt’s vindictiveness doesn’t put him out of place within the administration. In many respects, it reflects some of the trademark impulses of his boss, Donald J. Trump. But for staff, the episodes have proven exhausting and demoralizing.

Hupp, for her part, was legally obligated to tell investigators the truth about seeking a used mattress from the Trump International Hotel. And as Pruitt faces a mounting number of investigations into his conduct and spending at the agency, other aides are now finding themselves facing their own inquiries, with little assistance from their EPA boss.

Pruitt set up a legal defense fund this year to deal with those inquiries. But sources say he has not offered to use the fund to assist current and former aides with their own considerable legal expenses. Nor, according to sources, has he offered apologies or expressed remorse to those aides for their ongoing legal and personal woes. The mounting financial difficulties that some of those aides face has fueled distress even among those who consider themselves loyal foot soldiers for Pruitt.

Cleta Mitchell, the attorney overseeing the Pruitt legal defense fund, did not respond to requests for comment.

Asked for comment, an EPA spokesperson referred The Daily Beast to Pruitt’s comments before a House committee in May. “I am not afraid to admit that there has been a learning process and when Congress or independent bodies of oversight find fault in our decision-making I want to correct that and ensure that it does not happen again,” Pruitt said at the time. “Ultimately, as the administrator of the EPA, the responsibility for identifying and making changes necessary rests with me and no one else.”