I've known Plum Sykes since her best-selling author days, when she penned such fun-to-read tomes as Bergdorf Blondes and The Debutante Divorcée more than a decade ago.The longtime Vogue magazine contributor is witty, stylish, fun to gossip with (she knows everyone) and always helpful. When I was too timid to approach Victoria Beckham, who was on the front row of an Oscar de la Renta show at New York Fashion Week a few years back, Sykes marched right up to the notoriously sour-faced designer and made the introduction.

After taking a hiatus to marry and have children, Sykes is back on the author circuit to tout her latest novel, Party Girls Die in Pearls. During breakfast at the Hotel ZaZa when she stopped in Houston on an extensive U.S. book tour, the British author crisply ordered freshly squeezed orange juice and soft-boiled eggs and explained why she penned the murder mystery, which has been labeled "Clueless meets Agatha Christie."

CultureMap: So why did you decide to write a mystery?

Plum Sykes: I have a bit of an interest in the dark side and I also felt like for my readers who had had two romantic comedies, I didn't want to do that again. I might do that again in the future, you never know. But could I deliver something that gives them the Plum Sykes fun and froth and fashion and social stuff but with more of a story they can get their teeth into?

With a romantic comedy, we all know the ending. Do they get together or don't they? Yes, they do. You spend your whole time as a writer making it look like they're not going to get together but we all know they are. (With a mystery) there are a lot of possible endings.

CM: Why did you set the book in the '80s?

PS: I went to Oxford in the tail end of the '80s — '89 to '91. I had an absolute ball when I was there. Oxford is such an inspiring city. It was fun to look back at that time. And I wanted to set it before social media. I wanted it to be much more about the characters and the fun about finding out who did it through people's stories, not by tracking their cell phones.

CM: How do you go about writing a mystery?

PS: My great aunt was PD James' editor. When I first started to write the book, I went to see her and said, "Can you give me some tips about writing a mystery. How would PD do it?" And she said that PD James would write these big set pieces first and start the whole book around them. And she also said never have more than two dead bodies because it will confuse the reader. And never have more than one secret staircase. Two secret staircases is unbelievable, but you can get away with one.

And she talked to me a lot about what clues you put in. The clues can be real clues or fake clues that look like a clue but they're not. The whole time you're writing it, you're thinking about how can I manipulate the reader into thinking that this person is the wrong person, but you still get to the right person at the end? It's really fun to do.

CM: How have you changed in the past decade since writing your last book?

PS: I think having children and being married. I don't think it's changed me, but I've had a lots more ups and downs than when I was just single doing my first book, not a care in the world. Like this morning I got a message that both my girls have nitsheads— head lice. Having children makes your life much more real and grounded in reality. When I first met you I was working for Vogue and zipping around the world from party to party. In essence I'm the same person, but I've got much more life experience, which is really good. And you realize life isn't one party.

CM: How is promoting a book different from 10 years ago?

PS: I'm going to the same places but the social media is something that's changed. There's less concern about print media, because the truth is for a certain age group if it's not on their phone, they don't buy it.

CM: In The Debutante Divorcée, you wrote about the "Un-Googleable Man" — someone so rich that he could avoid social media. Can a person fly under the radar now or has that changed?

PS: ​You can't really be Un-Googleable now can you? It's not possible any more. But if you want to stay out of it, you can stay out of it pretty easily. The more you put out there, the more there is. The less you put out there, they forget about you so quickly. Some people don't do social media. But to be Un-Googleable is difficult.

CM: Any plans for a sequel to Party Girls Die in Pearls?

PS: I definitely want it to be a series. I love Agatha Christie. Did you ever read any of her books? They're murder mysteries and they're social comedies. They're filled with amazing details of the time and the place they're set in. They're very witty and very funny. But I wanted to make it very modern and very young.

CM: Will you keep the main characters in university?

PS: They're got years, they've got plenty of time. This book only takes a week. But I will take them to other places. They can go to (the trendy London club) Annabel's for the night and get back to write their essay. But readers who like series want them back in the same place.