Lindsay Lohan on 'Late Show with David Letterman': A clip

Lindsay Lohan appeared on "Late Show With David Letterman" Wednesday night -- their full encounter aired well past deadline -- but one little surprise was announced earlier in the day: Oprah Winfrey was on the show, too.

At least her voice was -- the former talk-show legend-turned cable mogul was on the receiving end of a phone call from Lohan and Letterman.

Letterman appeared not to be keen on the idea at first. After some prodding by Lohan and an audience chanting "Op-rah! Op-rah!" Letterman called Winfrey on the actress' cellphone, identifying himself in a disguised voice as "Lindsay Lohan's secretary."

"Who is this?" Winfrey asked, and Letterman, finally using his regular voice, admitted, "It's Dave, Oprah, it's Dave." "Oh my God," Winfrey laughed. "Very good, Dave! The David Letterman who's retiring?"

Letterman asked the chief executive of OWN how Lohan -- currently in the channel's low-rated "Lindsay" docuseries -- was doing months after production on the series wrapped, and nine months after the troubled actress left rehab.

"I think she's doing really OK," a somewhat muted Winfrey responded, adding "I think, you know, to have cameras following you around for every phase of your life, and you are trying to pull your life together, I think that's a really difficult thing, so, yeah, we're really pleased that she's making some progress."

Lohan started to tear up, and Letterman then quickly changed subjects: "Oprah, I've spent 30 years trying to pull my life together. Where the hell have you been?"

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Winfrey then reminded him that they both share the same "meditation teacher." To which Letterman responded: He has switched to something "that's really fantastic: Scientology."