'Believing the Lie,' by Elizabeth George

BELIEVING THE LIE, by Elizabeth George. Dutton,

610 pp., $28.95.

You know the joke. For 400 pages, Elizabeth George shows she's a master juggler when it comes to crime writing. Unfortunately, her new book is more than 600 pages.

And in the last 200 pages of "Believing the Lie," most of the balls she was juggling so adeptly land with a thud -- partly as a result of George's attempt to show she's more than a mystery writer, partly because she lets the individual stories get away from her.

It's a shame, because the Inspector Lynley series is one of the better ongoing detective series, bolstered by the smartly produced TV series seen on "Masterpiece Mystery" before the BBC unwisely pulled the plug. One of the oddities of the Lynley books is that they have such a distinctive British flavor -- this one is set in the Lake District -- though George herself is American. Despite that, her kinship is less with Janet Evanovich or Patricia Cornwell than with Ruth Rendell and Morag Joss.

Like those writers, George seems to be growing restless with the genre. "Believing the Lie," in fact, has much in common with Mike Leigh's great film, "Secrets and Lies," in which almost every character is guilty of hiding something. In "Believing the Lie," the consequences of repressing the truth can be tragic.

As the story opens, Lynley is dispatched to Cumbria for an undercover investigation into whether a muckety-muck's nephew, Ian Cresswell, accidentally drowned or was killed. Cresswell was living with a closeted Iranian man, and his other family members are all involved in some subterfuge or other. So is Lynley, who's having an affair with his boss following the senseless death of his wife. Perhaps the most intriguing mystery is why the Salma Hayek-like Latina wife of Cresswell's cousin is so nervous about her past being exposed.

Lynley -- a square-jawed, no-nonsense detective to the manor born -- is no stranger to the English 1 percent, which George plays off smartly in previous novels with his working-class assistant, Barbara Havers. But since Lynley is off the books here, he brings his friends Simon and Deborah along to help sniff out the situation, and as all these secrets come to the fore, it turns out that just about everyone had a motive for killing Cresswell. Add to that a couple of engaging subplots -- a tabloid writer also investigating the story, for example -- and those first 400 pages hum along nicely.

So what goes wrong? Once George tries to unite these individual stories with grander tragic themes, the characters lose their believability. There is no inevitability to whether they live or die. The Deborah St. James story line is particularly heavy-handed, as her Lucille Ball ditziness leads to the book's central tragedy.

Perhaps the problem isn't that George aims too high, but that she tries to stuff more into this book -- issues of tabloid media, child pornography, homosexuality -- than a Lynley mystery can handle. Rendell and Joss' greatest successes lie beyond the standard detective novel. Meanwhile, let Lynley be Lynley before seeking greater literary glory.