Donald Trump's grown son, Eric Trump, received a threatening letter on Thursday that is now the subject of an investigation by the Secret Service, FBI, and NYPD. The younger Trump received the letter at his home at 100 Central Park South in Manhattan, and his wife opened it.

A source told CBS News that the letter was postmarked from Massachusetts, and it warned that if Trump didn't end his bid for president, harm would befall his children. The letter also contained a suspicious white powder, although preliminary tests have not found it to be hazardous. Jeva Lange

Stephen Colbert began Wednesday's Late Show interview with actress and gubernatorial candidate Cynthia Nixon by warning New York Gov. Andrew Cuomo (D) to watch out for his "formidable opponent," because Nixon beat Colbert for a Grammy. He asked why Nixon was running under the banner "Cynthia for New York," not the more alliterative "Nixon for New York"? "My mother used to say that she grew up during World War II with a father named Adolph and then she lived through the 1970s with a husband named Nixon," she replied. "So I am aware of the dubious nature of my last name, but I have to say, if I was given a choice, I'd rather be the good Nixon than the bad Cuomo."

Nixon said she's running for governor "because I'm a lifelong New Yorker, and I love this state, and I just know we could do so much better." Colbert stopped her when she said Cuomo is governing like a Republican, asking for specifics. Nixon replied that New York should fully fund public education and be more like California and Oregon in leading the way on renewable energy, campaign finance reform, voting rights, and criminal justice reform.

Nixon said she's 100 percent serious about becoming governor, and Colbert stepped in to play "the governor's advocate," asking her if "we need another celebrity in office," and "should governor of New York be the first job you have" in politics? Nixon said she's not at all like President Trump, and celebrity is just a platform, and what matters is how you use it. She explained her support for legalizing recreational marijuana as primarily "a racial justice issue," not a drug one. "For all intents and purposes, for white people, marijuana has ... effectively been legal for a long time," she said, "and I just think it's time to make it legal for everybody else." Watch below. Peter Weber

Stephen Colbert kicked off Wednesday's Late Show by declaring he's "still riding high" from Tuesday night's interview with former FBI Director James Comey. "I'm not sure if the president saw the interview — I hear he doesn't watch TV hosts who don't share his lawyer," he joked, but one "seemingly out-of-nowhere" tweet suggests he might have. Either way, the interview "is already healing a nation," he said, because "James Comey is now friends with the Wu-Tang Clan." (Unlike Jeff Sessions.)

"Speaking of unlikely duos," Colbert said, CIA Director Mike Pompeo met with Kim Jong Un in North Korea — and he's not even secretary of state yet. "Apparently now, just anyone can have face-to-face talks with the leader of North Korea." He said he hopes the denuclearization talks are successful, and he couldn't believe "Trump kept something this big secret. How did he do it? I mean, the only possible explanation is that Michael Cohen paid him $130,000 to stay quiet about it."

The Late Show also imagined Kim's reaction to Pompeo's visit, and yes, it includes a Dennis Rodman reference.

Russian sanctions are dividing the White House, with U.N. Ambassador Nikki Haley announcing new sanctions Sunday — before Trump then scrapped the idea over the objections of his advisers. "We tried to get a follow-up from Nikki Haley, but it's so hard to reach her under that bus," Colbert said. Trump reportedly got so angry watching Haley announce the sanctions on TV, he shouted "Who wrote that for her?" at the screen. "Fun fact, Mr. President," Colbert said: "Not all women are under legally binding agreements about what they can say."

"Trump may be angry because he accidentally appointed someone competent," but Republicans are reportedly suspicious that Haley and Vice President Mike Pence are conspiring to run together in 2020, Colbert said. "That is absurd. Mike Pence can't be on a ticket with a woman who's not his wife." Peter Weber

On Wednesday, South Korea confirmed that it has been in talks with the U.S. and North Korea about negotiating a treaty to formally end the Korean War, which stopped in 1953 with an armistice signed by America, China, and North Korea. South Korean national security adviser Chung Eui-yong said that he, U.S. National Security Adviser John Bolton, and other Trump administration officials "held in-depth discussions" last week in Washington "on various ways of how to end hostilities and eventually establish a peace regime on the Korean Peninsula."

North Korean leader Kim Jong Un and South Korean President Moon Jae-in are meeting in the demilitarized zone (DMZ) on April 29, and President Trump confirmed Wednesday that he sent CIA Director Mike Pompeo to meet with Kim earlier this month to help lay the groundwork for a Trump-Kim summit in late May or June. On Tuesday, Trump said Kim and Moon "have my blessing to discuss the end of the war."

Negotiating a formal peace treaty would require the participation of China and the U.S. as well as the Koreas. A spokeswoman for China's Foreign Ministry said Wednesday that "China's attitude is open and supportive to any peaceful means to resolve the Korean Peninsula issue through consultations," but Cheng Xiaohe, a North Korea expert at Beijing's Renmin University, told The New York Times that Trump's hard line on trade "is complicating and undermining cooperation." If the U.S. wants to sign a treaty with Pyongyang, "it has to talk to China, and the United States has to recognize North Korea diplomatically," Cheng added. "A treaty is not a memorandum or a communiqué."

It's an open question what Pyongyang would give up or demand in the treaty — a withdrawal of America's 28,500 troops from South Korea would probably be a nonstarter, for example, but a reduction might align with Trump's goals and China's. You can read more about the sticking points at The New York Times. Peter Weber

Samantha Bee ended Full Frontal's two-week hiatus with an occasionally NSFW recap of the past week, from "election-ruining giant" James Comey's "creeping Trump gossip fatigue" book tour to outgoing House Speaker Paul Ryan's big announcement. "For the first time in his political career, Paul Ryan has offered the nation something we actually want: his retirement," Bee said. After thrashing Ryan and his legacy for a few minutes, she used Beyoncé's Coachella performance to show that it's not really that hard to hire women and people of color, proving her point with 10 black people doing Jerry Seinfeld impressions.

Bee turned to the news that President Trump's lawyer/fixer Michael Cohen also apparently worked for Sean Hannity. "Why the f--k did Sean Hannity — the guy who made $36 million last year? — retain a graduate of the actual worst law school in the country, a guy whose whole business model seems to be built around blackmailing mistresses?" she asked. Hannity said he innocently asked Cohen "exclusively almost" about real estate, and Bee decided he "must have done something so much worse" than infidelity. She had a suggestion, keying off a clip where a lawyer said Cohen knows "where all the bodies are buried." "Whoa, is Sean Hannity a serial killer?" Bee asked, melodramatically.

"I know what you're thinking: You can't just throw together a bunch of scary buzzwords and out-of-context clips to support an outrageous conclusion, and normally I would agree with you," Bee said. "But you know who does that all the time? Sean Hannity." She showed some examples. "His whole show is just an hour-long list of lies and conspiracy theories, but people think it's news because he doesn't sweat as much as Alex Jones and because he's on a channel that calls itself news," Bee said. So she used "deceitful editing to reach an outrageous conclusion," and it's pretty harsh and NSFW, and you can watch below. Peter Weber

It was the hottest ticket in Saudi Arabia — an invitation to a private screening of Black Panther in Riyadh.

On Wednesday, the first cinema to open in Saudi Arabia in more than 30 years welcomed excited moviegoers. In the 1980s, the kingdom prohibited public movie screenings, due to ultraconservative clerics labeling Western movies as sinful, but Crown Prince Mohammed bin Salman lifted the ban amid a series of reforms. By 2030, Saudi Arabia plans on hosting 300 movie theaters with 2,000 screens.

Just two weeks ago, AMC signed a contract to open the inaugural theater, and public screenings are expected to start Friday. Government censors will have the final say on what moviegoers get to see — in Black Panther, a final scene featuring a kiss has been cut — and the theaters will likely be separated with women and related men sitting in the family section and single men in another. "It's a new era, a new age," moviegoer Rahaf Alhendi told The Associated Press. "It's that simple. Things are changing, progress is happening. We're opening up and we're catching up with everything that's happening in the world." Catherine Garcia

A group of House Republicans keeps ratcheting up pressure on Deputy Attorney General Rod Rosenstein to hand over documents related Special Counsel Robert Mueller's Russia investigation and the FBI's Hillary Clinton email investigation, and Democrats say President Trump's allies are mostly trying to create a pretext for Trump to fire Rosenstein. Trump is reportedly furious at Rosenstein, who oversees the Mueller investigation and approved last week's raid on Trump's lawyer/fixer Michael Cohen.

Three House Republicans — Intelligence Committee Chairman Devin Nunes (Calif.), Oversight Committee Chairman Trey Gowdy (S.C.), and Judiciary Committee Chairman Bob Goodlatte (Va.) — have feuded with Rosenstein over documents that Rosenstein may not be able to turn over because, as he told them in letter Monday, they "may relate to an ongoing investigation, may contain classified information, and may report confidential presidential communications." The Justice Department typically does not give Congress documents from open law enforcement cases.

On Wednesday, Rep. Jarrold Nadler (D-N.Y.) said Goodlatte had given him notice that he intends to subpoena former FBI Director James Comey's memos on Trump. "If House Republicans refuse any accommodation short of the Department of Justice handing over custody of these documents — which it cannot do — I fear the majority will have manufactured an excuse to hold the deputy attorney general in contempt of Congress," Nadler told CNN. And the contempt motion, he added, might give Trump "the pretext he has sought to replace Mr. Rosenstein with someone willing to do his bidding and end the special counsel's investigation." The Republicans say they are just exercising their proper oversight duties.

Also, two of Trump's top allies in the House, Reps. Mark Meadows (R-N.C.) and Jim Jordan (R-Ohio), met with Rosenstein on Monday to press for more documents on the conduct of law enforcement officials involved in the Russia and Clinton investigations, The Washington Post reports. "Trump and Meadows spoke at some point after the meeting, the three people said, but they declined to share details of the exchange." Peter Weber

Authorities in Philadelphia are investigating the suspicious death of former National Security Adviser H.R. McMaster's father, H.R. McMaster Sr., several people told 6 ABC News.

The elder McMaster, 84, died April 13 at a nursing home where he was recuperating from a stroke. 6 ABC News reports that investigators are looking into allegations that McMaster fell and hit his head, then was put in a chair and died without receiving proper care. McMaster's family was also reportedly told by some staff members at the facility that records related to his death had been falsified.

The nursing home, Cathedral Village, told 6 ABC News on Wednesday that on the day McMaster died, they notified the Department of Health and started an investigation into the allegations. The Pennsylvania attorney general's office called the incident "tragic," and said its investigation is in the "very early stages." Catherine Garcia