Beginning this evening, "Piers Morgan Tonight" welcomes the return of "Guest Host Week," and it does so by inviting a pair of icons boasting a combined eight decades of television chops.
With the incomparable Regis Philbin keeping Piers Morgan's seat warm, the legendary David Letterman pulls up the guest's chair, as the two longtime friends fill the hour with candid commentary and engaging exchange.
As the topic turns to more serious matter, Philbin asks Letterman to review his first show following September 11th:
"I remember that night and I remember not wanting to go back, not feeling ready to go back, but knowing we had to go back," says Letterman. "And, you know, my concerns were minimal compared to people who...really suffered."
Admittedly uncertain about what was appropriate, the "Late Show with David Letterman" host says he took his cue from the mayor:
"I felt like Rudy Giuliani kept - kept saying go back to work, people - not to me, but generally...that we - we've got to live our lives and we have to go back to work."
Watch the clip, listen to the interview, then tune in tonight at 9 p.m. as two of the most-decorated hosts in the history of modern television talk healthy and family, politics and cigar smoking.
» Follow Piers Morgan Tonight on Twitter