In short, it was a recipe for at least some drama. Here are the top eight contentious moments (so far):
1. Gowdy vs. Cummings, Part 1
Facing accusations from Democrats and even comments from a Republican that the committee has a political purpose -- to damage Clinton's presidential ambitions -- Rep. Trey Gowdy (R-S.C.), the committee chairman, wanted to make clear that Clinton is "one important witness" "among hundreds."
"Not a single member of this committee signed up to investigate you or your e-mail," he said.
In his opening statement, Rep. Elijah Cummings (D-Md.) countered Gowdy. "The truth, the whole truth, and nothing but the truth," he said slowly, then repeated it. "The truth, the whole truth and nothing but the truth."
Cummings then slammed what he saw as political motives.
"The problem is that the Republican caucus did not like the answers they got from those investigations, so they set up this select committee with no rules, no deadline and an unlimited budget. And they set them loose, Madam Secretary, because you're running for president."
2. Rep. Peter Roskam (R-Ill.) vs. Clinton and her notes
In the first round of questioning, Roskam noticed Clinton turning to her aides seated behind her to receive notes while he was talking.
Roskam offered to "pause" while she read those notes. An apparently surprised Clinton stated that she could go do more than "one thing at a time, Congressman."
A few minutes later, Roskam offered again to let Clinton read the notes she was being passed as he spoke. This time Clinton laughed in patronizing manner.
3. Rep. Martha Roby (R-Ala.) vs. Clinton and her e-mails
When it was her turn, Roby wanted to zero in on an e-mail exchange between two staffers on the State Department's Libya desk purportedly saying that Clinton asked whether the State Department still had a presence in Benghazi.
A classic fundamental disagreement over the underlying facts began. Clinton said that of course she knew the State Department had staffers in Benghazi; Roby said the e-mails say something different.
Clinton replied: "Congresswoman, I'm sorry. I have no recollection of, or no knowledge of -- of course."
It just so happens that this particular e-mail exchange was printed out in a prepared booklet for Clinton and her questioners. Roby urged her to open the book and even gave her the page number. Clinton demurred.
A few exchanges later, Roby once again urged Clinton to open the book and read the e-mail exchange that Clinton said she couldn't recall. Once more, Clinton demurred.
The two had another back-and-forth when Roby wrapped up her questions with a comment: "We will certainly never know what the outcome would have been if there had been more agents that night."
Even though it wasn't her turn to speak, Clinton jumped in. There have been eight other investigations, including bipartisan congressional reviews and an official Accountability Review Board query set up by the State Department, Clinton pointed out, insinuating Roby hadn't read that board's findings.
Clinton wanted to frame the narrative that the book has been closed on what the United States did wrong that night. But even what those official reports said is apparently still up for debate. Roby said the Accountability Review Board found "security was grossly inadequate"; Clinton said it found "there were deficiencies which we have moved to correct."
4. Clinton defends State Department officials
In response to Rep. Lynn Westmoreland (R-Ga.) wondering out loud how well security officials in Benghazi did their job, considering people died, Clinton said she could not allow a comment on the record "criticizing or disparaging" those officials.
"The diplomatic security professionals are among the best in the world," she said.
This is a theme she would return to repeatedly.
5. Rep. Jim Jordan (R-Ohio) vs. the Obama administration's motives
Many of the contentious exchanges were relatively understated -- until Rep. Jim Jordan (R-Ohio) got a chance to question Clinton.
The founding member and chairman of the conservative House Freedom Caucus was pushing a well established (and well litigated) narrative that in the days after the attacks, Clinton said one thing privately about what caused them and another thing publicly.
Jordan was laying out one of the right's main allegations -- that the Obama administration covered up trouble in Libya 56 days before an election because it was one of the few countries where things were going well. (Obama and administration officials have said that narrative "defies logic.")
"Calling it an attack is like saying the sky is blue!" Jordan yelled, while Clinton rested her head in her hand, apparently almost amused at the allegations laid out before her.
Clinton replied: "I wrote a whole chapter about this in my book, 'Hard Choices.' I'd be glad to send it to you, Congressman."
6. Gowdy vs. Cummings and Rep. Adam Schiff (D-Calif.)
More than three hours in, voices on both sides started rising. Gowdy took a turn grilling Clinton about her connection to friend and confidant Sidney Blumenthal, who sent Clinton at least 25 memos in 2011 and 2012 purporting to have intelligence about Libya and elsewhere.
The accuracy and motives of the information he sent to Clinton, which made up about a third of her 900 e-mails released about Libya, have been questioned.
Before the hearing was about to break, Cummings interjected for Clinton, demanding Gowdy release the transcript of the committee's private discussions with Blumenthal. He was implying that Gowdy was asking Clinton questions he already knew the answers to.
A shouting match involving Gowdy, Cummings and Schiff ensued. Clinton silently sat back in her chair and watched the committee members duke it out.
Then everyone took a much-needed break.
7. Roskam vs. Clinton's ego
A little less hangry, the hearing resumed about 30 minutes later. But the contentious moments kept coming.
Roskam, who had been one of the most forceful questioners of Clinton, pressed her on her media strategy after the attacks. "You were working to make this the story of the day, isn't that right?" he asked.
Clinton, no surprise, denied that was the case.
And if you watch the clip above, The Washington Post article Roskam is talking about was published in October 2011. Clinton's team gave a Washington Post reporter a timeline of how she helped orchestrate the U.S.'s 2011 military intervention in Libya. The subsequent article was titled "Hillary's war: How conviction replaced skepticism in Libya intervention."
8. Jordan vs. Clinton's own words
Heading into dinner time, Jordan continued his line of attack questioning the accuracy of Clinton's statements in the days after Benghazi. At issue was whether she tried to blame the attacks on a crudely made, inflammatory video, "The Innocence of Muslims."