You get a guest star! You get a guest star!

This week’s “Saturday Night Live” did not start in its typical spot with a frowning Alec Baldwin as President Trump in the Oval Office.

Instead, the cold open was a sendup of MSNBC’s “Morning Joe,” with Alex Moffat and Kate McKinnon playing outrageously flirty versions of Joe Scarborough and Mika Brzezinski. Mikey Day, as their co-host Willie Geist, was along as an awkward third wheel to a couple that announced their engagement last spring.

But the real stars of the sketch were alumni of “S.N.L.” making guest appearances: Fred Armisen and Bill Murray.

Mr. Armisen returned as Michael Wolff, the polarizing author of “Fire and Fury,” the book about the Trump White House that has gripped Washington (and the country) for more than a week. When asked what he didn’t include in the book, Mr. Armisen offered up this: “baby races.”