Princess Di act hits Sin City

An impersonator, her sister, more improbable characters get into a casino full of trouble.

Chris Bohjalian has a type. His recent thrillers are about glamorous, imperiled women who may not be trustworthy but whose senses of humor makes us like them anyway.

The author of “The Flight Attendant” and “The Lioness” is true to type with “The Princess of Las Vegas,” who has an adventure that is as dangerous and improbable as those experienced by the heroines of Bohjalian’s previous books. She’s Crissy Dowling, who exploits her resemblance to Diana Spencer in a Vegas cabaret act where she sings British pop songs, tells stories about royals and avoids mentioning the fact that Diana is, um, dead.

Quite a few unlikely things happen in “Princess,” in which every character has at least one secret as big as that crazy orb thing that now dominates the Vegas strip: Crissy’s sister Betsy is almost an exact double who suddenly moves to Sin City with her unscrupulous lover. The mob wants to swallow Crissy’s low-rent casino. Betsy has a recently adopted daughter who may not be what she seems. And Crissy’s former lovers include a senator who’s in a tight re-election race.

Bohjalian writes with verve and humor, and his depiction of a seedy, past-its-prime casino feels just right, so I was willing to swallow all of the above. It also helps that Bohjalian roots the improbabilities in something real: the dynamic between siblings who always have been rivals and who have found it easier to ignore each other than to improve their relationship after the death of their mother.

Which explains their chilly re-meeting, narrated by Crissy:

“Apparently, the last year had not been kind to her — which felt right. Kill your mother and you should be cursed with sallow skin and early-onset gray hair. ‘You made it,’ I said. We embraced, and it was awkward, as if we had lost our muscle memory as siblings.”

Like her foremothers in “Flight Attendant” and “Lioness,” Crissy makes frequent disastrous decisions that exasperate us but, unlike those two, “Princess” finds Bohjalian trying an interesting experiment that really pays off: We’re not entirely sure if we’re supposed to identify with Crissy.

As Crissy’s behavior, fueled by surgical-grade meds, becomes increasingly peculiar, Bohjalian dangles the possibility that Betsy, who’s more practical despite the predicament into which she has stumbled, is the character who deserves our sympathies.