All of the pieces are finally in place for the impeachment trial of President Donald Trump. On Wednesday, Speaker Nancy Pelosi named a slate of seven managers—House members who will act as prosecutors in the trial—shortly before the House voted to formally submit the articles to the Senate. Later this week, Chief Justice John Roberts will swear in all 100 senators. The trial itself will begin in full next week.

While the stage may be set, new characters keep joining the production. The House Intelligence Committee released a new batch of evidence for its case on Tuesday night, obtained from Lev Parnas—a Ukraine-born associate of Trump lawyer Rudy Giuliani. Federal agents arrested Parnas and a colleague in October for violating federal campaign-finance laws; since then, he’s offered to cooperate with House investigators on the impeachment inquiry. The records include conversations between himself and other key participants in the scandal, providing a rare glimpse into its internal workings.

House Democrats used the release to pressure the White House and the Senate into additional disclosures. “These documents—and those recently released pursuant to Freedom of Information Act—demonstrate that there is more evidence relevant to the President’s scheme, but they have been concealed by the President himself,” California Representative Adam Schiff and three other committee chairs said in a statement. “All of this new evidence confirms what we already know: the President and his associates pressured Ukrainian officials to announce investigations that would benefit the President politically.”

What the revelations do underscore is how little Americans actually know about one of the worst political scandals in the nation’s history—and the fierce urgency of shedding light on it.

Their statement highlights a tightrope that House investigators must navigate over the next few weeks and months. Tuesday’s new evidence won’t fundamentally change either side’s approach in the upcoming trial; Parnas did not directly communicate with the president himself, making its relevance to his impeachment somewhat limited. What the revelations do underscore is how little Americans actually know about one of the worst political scandals in the nation’s history—and the fierce urgency of shedding light on it.

Some of the new evidence confirms or fleshes out facts that were already apparent. Among the documents is a letter drafted by Giuliani for Ukrainian President Volodymyr Zelenskiy declaring that the former New York mayor was acting on Trump’s personal behalf. Undated slips of paper from the Ritz-Carlton in Vienna provided by Parnas also show a series of notes about the Giuliani clique’s activities in Ukraine. One of the bullet points reads “get zalensky [sic] to announce that the Biden case will be investigated,” undercutting the already tattered White House claim that Trump was merely interested in Burisma—the Ukrainian energy company where Biden’s eldest son, Hunter, once held a board seat—or in corruption writ large in Ukraine.