She is behind two book series (Alex Barnaby is her other heroine), stand-alone books written with a co-author, a website, a newsletter, merchandise and popular tours.

But while it is undoubtedly the product of a recipe, this smart, quirky style isn't as easy as it looks, even if Evanovich has it down pat.

After a slow start, Stephanie enters centre stage after a bank robbery. Dragging Loretta Rizzi back to face her court appearance seems so simple - but then Loretta can't make bail and Stephanie is left looking after her misfit teenaged son Mario, better known as Zook. She hauls him back to Joe Morelli's place - after all, Loretta is Morelli's cousin.

Morelli is the hunky Italian police officer, Stephanie's childhood sweetheart and regular squeeze, who is part of a sexual conundrum in which she finds herself.

Ranger, another partner in that same conundrum, inevitably ends up helping out when a body appears in Morelli's basement, plus there are links to a recently released bank robber ... who happens to be Loretta's sister, who has a long-standing grudge against Morelli.

Sound complicated? Fear not. The grey matter is rarely stretched by an evening on the couch with Morelli and Ranger.

This is slick entertainment. There are still plenty of laughs, but it is hard to avoid the feeling that Evanovich is stretching it. After all, this is not the kind of crime fiction that taps into current affairs, brings in a whole new cast and offers sophisticated character development.

Same characters, same tensions, new one-liners for the same old reasons. The Stephanie Plum series may make Fantastic Fifteen, but it will be a tawdry, terrible 20 if Evanovich doesn't call time soon.