Michael Douglas, Diane Keaton find each other, later, in Rob Reiner's 'And So It Goes'

The story behind "And So It Goes" -- in which a narcissistic Realtor (Michael Douglas) becomes a human being under the guidance of a widowed wannabe cabaret singer (Diane Keaton) -- began with another Rob Reiner movie, "The Bucket List."

"During the press junket, all the journalists asked us 'What's on your bucket list?'" said Reiner, whose new movie opens Friday. "And Jack Nicholson would always say, 'One more great romance.' And I thought, 'That's an idea for a movie.' I love the idea of two people finding each other later in life."

With a script by Mark Andrus ("As Good As It Gets"), "And So It Goes" involves Oren Little (Douglas), an insufferable, egotistical real estate agent who discovers 1) that his estranged son is going to prison; 2) that he has a granddaughter, Sarah (Sterling Kerins), and 3) that Oren is expected to care for her while his son is in stir. Oren doesn't want to. Enter Leah (Keaton), the lady next door, who becomes the mother Sarah never had.

It's a romantic comedy, but it's not all sweetness and light. The story of Sarah's mother, for instance, is decidedly disturbing.

"That's my favorite kind of movie," Reiner said. "Some humor, but also some deeper emotional stuff going." A perfect example, he said, was "Stand By Me," his 1986 classic and a movie that's decidedly unsettling. Even more unsettling than the toupee Reiner wears as Leah's piano player.

"Any chance you get to wear a hairpiece that's totally undetectable is always a plus," Reiner joked. "Basically, what happened was there was a cat who became the mascot on the set and, unfortunately, it died. We didn't know what to do with it, so we just buried it, basically, on my head."

While old friends with Douglas, Reiner said he'd never worked with Keaton, who, during one scene, has to audition for a club owner played by Frankie Valli, with recent Emmy winner Douglas ("Behind the Candelabra") sitting beside him.

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"Right before the first take, I said, 'You nervous? You have to sing in front of Frankie Valli.'" She said, 'Frankie Valli? Where's Frankie Valli?' She had no idea.

"She said, 'Oh, my God, why did you do that??!!' I said, 'You'll be fine. Besides, I have to play piano in front of Liberace.'"