1. The refused handshake. Is it cold in here? When Trump and Clinton took the stage, they skipped the customary greeting, instead acknowledging each other with a curt nod. 

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>> See the moment here

>> PHOTOS: Second presidential debate

2. Trump's lurking. Throughout the night, Trump roamed the stage, often looming behind Clinton as she answered questions. 

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>> Trump's hovering, pacing at debate set social media ablaze

3. Locking her up? As Trump shifted the topic from the controversy over his lewd comments to Clinton's email scandal, he threatened to jail her.

"If I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation because there has never been so many lies, so much deception," he said. "There has never been anything like it. And we're going to have a special prosecutor."

Clinton urged viewers to fact-check Trump's statements, adding, "You know, it is just awfully good that someone with the temperament of Donald Trump is not in charge of the law of the country.”

“Because you’d be in jail,” he replied as several people in the audience cheered.

>> Watch the moment here

>> Donald Trump to Hillary Clinton: If I were president, 'you'd be in jail'

4. Abe Lincoln gets a shout-out. Prompted by the leak of an excerpt from a Clinton speech where she advised having "both a public and private position on certain issues," Clinton fielded a question about whether it is acceptable for politicians to be "two-faced."

"As I recall, that was something I said about Abraham Lincoln after having seen the wonderful Steven Spielberg movie called 'Lincoln,'" she said. "It was a master class watching President Lincoln get the Congress to approve the 13th Amendment. It was principled, and it was strategic.

"And I was making the point that it is hard sometimes to get the Congress to do what you want to do and you have to keep working at it. And, yes, President Lincoln was trying to convince some people, he used some arguments, convincing other people, he used other arguments."

Trump pounced, responding, "Well, I think I should respond, because — so ridiculous. ... She got caught in a total lie. Her papers went out to all her friends at the banks, Goldman Sachs and everybody else, and she said things — WikiLeaks that just came out. And she lied. Now she’s blaming the lie on the late, great Abraham Lincoln."

He added, "OK, Honest Abe, Honest Abe never lied. That’s the good thing. That’s the big difference between Abraham Lincoln and you."

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5. Their "Kumbaya" moment. After an evening of mud-slinging, the candidates were asked to name one positive quality about each other. Clinton's response? 

>> Here's how Trump and Clinton responded when asked what they respect about each other

>> Click here to see the exchange