In the wake of Bill O’Reilly’s ouster, Fox News Channel issued a talking points memo of its own: Its primetime lineup will maintain a similar tone and attitude even without the person who was arguably the network’s most recognizable anchor in place.

Tucker Carlson, who has held forth in primetime at 9 p.m. and delivered solid ratings, will move to O’Reilly’s 8 p.m. slot starting Monday, April 24. Fox News will fill Carlson’s former berth with its panel show, “The Five,” which will be co-anchored by Kimberly Guilfoyle, Dana Perino, Bob Beckel, Greg Gutfeld, Jesse Watters and Juan Williams will Sean Hannity will remain at 10 p.m.

Additionally, Martha MacCallum will stay at 7 p.m. in a program that will be re-titled “The Story” starting April 28. She has been hosting a program centered on the first 100 days of President Donald Trump’s administration. Eric Bolling, a longtime “Five” contributor and “O’Reilly Factor” substitute anchor, will get a new 5 p.m. show starting May 1.

Getting a new lineup is critical for Fox News. For decades, its primetime schedule remained inviolate. O’Reilly, Hannity (with and without Alan B. Colmes) and Greta van Susteren led three hours of programming that won more and more viewers as the years passed on, eventually drawing more audience than rival CNN. But the network’s audience is accustomed to stability. When Megyn Kelly took over the 9 p.m. slot in 2013, it marked the first time the network had shaken up primetime since 2002.

O’Reilly leaves big shoes to fill, ratings-wise. During his last full week on Fox News Channel, O’Reilly saw his viewers between 25 and 54 – the audience most coveted by advertisers – rise 42%, while overall viewership surged 28%. He regularly delivered between 3 million and 4 million viewers every weekday – people who would then stick around for anchors at 9 p.m. and 10 p.m. On Monday night, Tucker Carlson delivered nearly 2.7 million viewers at 9 p.m., compared with 3.1 million viewers for an “O’Reilly Factor” with a substitute host.

The shifts could leave Fox News vulnerable to new competition. At 9 p.m., MSNBC’s Rachel Maddow has gained new audience. In March, she won more viewers between 25 and 54 than any of Fox’s three primetime programs. And “The Five” will debut in primetime as CNN launches a special week of “The Lead with Jake Tapper” in that time slot.