The office building’s lights were turned off, casualties of a government shutdown, when the team from Skadden, Arps, Slate, Meagher & Flom arrived to meet with Justice Department officials in a last-ditch bid to avoid registering as an agent of Ukraine.

It was October 2013, and Lawrence Spiegel, the law firm’s general counsel, had flown into Washington from New York on his birthday to attend the meeting with Greg Craig, a prominent Skadden partner whose work for Ukraine had drawn the Justice Department’s scrutiny. Remembering the midday meeting, Spiegel said in a D.C. courtroom Monday that it was held in what “appeared to be sort of a secured location—it sort of had this feel like we were almost entering a bank vault, in terms of where we were.”