CBS News’ Margaret Brennan had an interesting conversation with the new Russian ambassador to the United States, Anatoly Antonov. He said the Russia investigation severely complicates his work. Many U.S. officials even refuse to meet him. Source

President Trump tweeted over the weekend that he fired Michael Flynn just 24 days into his term because “he lied to the Vice President and the FBI.” The tweet sparked new questions about whether the president has obstructed justice. Major Garrett reports. Source

The U.S. and South Korea began one of the largest combined Air Force exercises in history on Monday. The show of force comes a week after North Korea test-fired its most advanced missile yet. National security adviser H.R. McMaster says the potential for war with the North is growing every day. Ben Tracy flew with American crews in Japan. Source

CBS News business analyst Jill Schlesinger joins “CBS Evening News” with details on how the tax plan will affect you. Source

Wall Street signaled its approval Monday of the tax cuts passed by the Republican-controlled Congress. The Dow closed at a record high, with financial stocks leading the way. President Trump called the overhaul a Christmas gift. What’s in it? CBS News chief congressional correspondent Nancy Cordes unwraps the tax package. Source

Manchester Orchestra returns to Saturday Sessions after releasing their latest album, “The Million Masks of God.” The band formed in 2004, and since then, they have played the main stages at Bonnaroo and Lollapalooza and had hits on the alternative charts. The band joins “CBS This Morning: Saturday” to perform “Telepath.” Source

Manchester Orchestra returns to Saturday Sessions after releasing their latest album, “The Million Masks of God.” The band formed in 2004, and since then, they have played the main stages at Bonnaroo and Lollapalooza and had hits on the alternative charts. The band joins “CBS This Morning: Saturday” to perform “Keel Timing.” Source

Dan Brown’s books have sold more than 200 million copies around the world. His latest novel, “Origin,” features the return of symbologist Robert Langdon. This time, Langdon is trying to unlock a discovery that will help answer two fundamental questions of human existence: Where do we come from and where are we going? Brown joins “CBS This Morning” to talk about his latest thriller, which has been on the bestseller list for nearly two months. Source

Manchester Orchestra returns to Saturday Sessions after releasing their latest album, “The Million Masks of God.” The band formed in 2004, and since then, they have played the main stages at Bonnaroo and Lollapalooza and had hits on the alternative charts. The band joins “CBS This Morning: Saturday” to perform “Bed Head.” Source

Ashley Graham says she was told early on she wouldn’t succeed in a modeling world known for stick-thin women. Agents told her she would never be on the cover of a magazine because she was “too fat.” Instead, she became the first curvy model to appear on the cover of the Sports Illustrated Swimsuit Issue. Graham talked to “CBS This Morning” co-host Gayle King about rising above the bullying she suffered in school; how the term “plus-size” is divisive to women; and the advice she gives to girls who ask about pursuing a career in modeling. Source