What to expect: First up on Wednesday is the top U.S. diplomat in Ukraine Bill Taylor, whose explosive closed-door testimony last month has been described by many Democrats as the most damaging to Trump.

State Department official George Kent will also appear on Wednesday. The committee will interview former U.S. Ambassador to Ukraine Marie Yovanovitch on Friday.

The public hearings will begin with roughly 45 minutes of questioning from Intelligence staff, followed by questions from committee members.

Sources familiar with the layout of the hearings say they were deliberately organized to ensure the substance of their testimony is heard at the top.

Democratic House aides told Axios that House Intel chair Adam Schiff chose to present Taylor, Kent and Yovanovitch first because they believe each has "unimpeachable character," as one aide described it, and are apolitical career officials.

"You've got to have a blockbuster opener and closer. That's why we went with Taylor and Kent," a second aide said.

"Yovanovitch was the first victim of the president's scheme with Giuliani,” the aide added. That draws the "sympathy of the audience."

Schiff's team has asked Democratic members not to share any information about their preparations ahead of the hearings.

Schiff himself will be laying low and will not do any media before Wednesday, one aide said.

And while a lot of their prep is being spent on how to counter and preempt Republicans' "theatrics," Schiff has directed members and staffers to be "serious as f--k," as the aide described it, and advised them to treat the hearings as a somber moment in American history.

Behind the scenes: House Speaker Nancy Pelosi was not happy with how House Judiciary Chairman Jerry Nadler — who, according to House rules, will eventually have to take ownership of the impeachment fight — handled the Russia hearings, particularly Special Counsel Robert Mueller’s hearing, two Democratic sources familiar with her thinking tell Axios.

She thought Nadler lost control of the hearing and let it devolve into confusion.

This is why she has kept Schiff in charge and has commandeered the impeachment process behind the scenes.

This has also led to talk of lending Intelligence Committee staff to the Judiciary Committee when the inquiry ultimately lands there, the sources said.

What's next: More public hearings will follow. One of the aides said they hadn’t settled on week two witnesses yet, but thought Lt. Col. Alexander Vindman, a decorated military officer and the NSC's director of European Affairs, would be a natural closer.

"He'd come in his dress blues — how powerful would that be?" the aide said.

Go deeper: Inside Republicans' defense strategy for impeachment