This week, we’re producing episodes of “The Daily” from The New York Times’s Washington bureau.

The impeachment inquiry is entering a pivotal phase as Congress returns from recess. The White House’s strategy to block the investigation is beginning to crumble, with five administration officials set to testify before House investigators.

On Monday, those committees heard testimony about why the president removed the longtime ambassador, Marie L. Yovanovitch, just two months before the call in which he asked the Ukrainian president for a favor. Today, we look at how Ms. Yovanovitch ended up at the center of the impeachment process.

Guests: Sharon LaFraniere, an investigative reporter based in Washington, and Rachel Quester and Clare Toeniskoetter, producers for “The Daily.” For more information on today’s episode, visit nytimes.com/thedaily.

Background coverage:

• Marie L. Yovanovitch told House investigators that she was removed from office on the basis of “false claims by people with clearly questionable motives.”
• The effort to pressure Ukraine so alarmed John Bolton, then the national security adviser, that he told an aide to alert White House lawyers. “Giuliani’s a hand grenade who’s going to blow everybody up,” an aide quoted him as saying of President Trump’s personal lawyer.