Of the many Trumpworld associates caught up in Robert Mueller’s Russia web, few have faced as intense media scrutiny as Michael Flynn. Trump’s first national security adviser, who repeatedly failed to fully disclose his many lobbying and business ties, and who repeatedly seemed to mix his government and private-sector work, is reportedly a central target for Mueller’s team of prosecutors as they move closer to potential indictments. And as Flynn has realized, being in Mueller’s crosshairs is expensive.

As my colleague Abigail Tracy has previously reported, a top-tier white-collar lawyer in Washington will typically charge between $750 and $900 per hour. Given that a single F.B.I. interview could require 40 to 60 hours of prep work, even the lowest level White House staffer ensnared in Mueller’s probe could end up on the hook for $30,000 to $54,000. Flynn, meanwhile, has hired at least seven lawyers, BuzzFeed News reports. He has enlisted one of the most prestigious law firms in Washington, D.C., Covington & Burling, which specializes in the extremely expensive art of preparing clients for congressional inquiries, both through legal research, strategy, and preparing their clients for congressional hearings. According to a source close to Flynn, the costs will “certainly be into the seven figures.”

Generally, the preparations involve several hours of practice during “moot” panels, in which several lawyers will grill Flynn for at least four hours, while playing the roles of several different senators and congressmen, even occasionally bringing in lamps that mimic the harsh glare of television lighting. Michael Caputo, another Trump aide who has hired his own lawyers to represent him in the Mueller probe, told the Daily Beast that a single “moot” session could cost up to $10,000 if only two lawyers are involved; Flynn, who faces multiple Senate and House hearings, will likely need to prepare for several hearings. Mueller’s dream team is even more formidable: some 16 highly accomplished prosecutors and attorneys with expertise in money laundering, corruption, fraud and foreign bribery, as well as a large support staff, all fully funded by the U.S. government.

Like Flynn, other Trump associates connected to the White House, Trump campaign, and Trump Organization, are facing vertiginous legal fees to protect themselves. Paul Manafort, a former lobbyist and Trump campaign manager with ties to pro-Russia groups, has changed lawyers several times, largely due to the nature of Mueller’s probe encompassing international legal issues, but also reportedly for financial reasons. Caputo himself has said that he liquidated his children’s college fund to pay for his legal bills. Flynn, meanwhile, is following an age-old Washington tradition: his family have set up a legal defense fund to defray costs and pay said Covington lawyers. Perhaps sensing the delicacy of the situation at hand, the Web site’s description of the fund takes unusually great pains to remind donors that they will only accept money from U.S. citizens and permanent residents.