One winter’s night, at a charity gala in a Chicago gallery, a con is on. Liz Dawson, masquerading as art consultant Elizabeth Hastings, finds the mark she has set her sights on, Mrs. Reed. After her bogus sob story elicits the sympathy of the wealthy collector and philanthropist, Liz then piques her interest with the offer of a Keith Haring painting that doesn’t exist. Eventually they part, Mrs. Reed walking away with one of Liz’s business cards, Liz making off with Mrs. Reed’s ruby ring.

Krysten Ritter hooks us with this deft opener to her new novel and reels us in. The Los Angeles-based actor (star of the Marvel series “Jessica Jones”) and author follows her 2017 debut, “Bonfire,” by delivering another thriller fronted by a gutsy, feisty female protagonist. “Retreat” begins by showing what smooth-operating scammer Liz is capable of. But as Ritter thickens her plot and ups the stakes, swapping con tricks for corpses, the book turns into a mystery, one that its antiheroine tries frantically to unravel.

Liz’s problems start small but come in threes. Mrs. Reed’s son plagues her with concerns, and then threats, about the $50,000 investment she persuaded his mother to make for a painting she will never see. A hotel hounds her for unpaid bills. Surely it won’t be long before the police are questioning her about the scarf she left behind at the scene of a recent crime.

Fortunately, Liz is able to leave these cares far behind. When a golden opportunity comes her way to manage an art installation in Casa Esmerelda, an oceanfront villa in a luxury Mexican resort, she enthusiastically seizes it. The property’s owners, venture capitalist Oliver Beresford and his wife, Isabelle, will be in Bali, giving Liz a week to relax and recharge in their gated private enclave. Soon she is sampling the delights of Punta Mita and mingling with the community’s super-rich residents. Some of them mistake her for Isabelle Beresford. Rather than correct them, Liz decides to keep up the pretense — no great stretch for someone so used to sloughing off and trying on one alias after another.

But while hiking with her new friend Tilly, Liz is horrified at coming across two dead bodies. “This is not what I signed up for,” she tells herself. “I don’t do death and danger — not real, life-threatening danger.” To reveal more here would be to spoil all. Suffice it to say, Liz’s grisly discovery heralds a change in her fortunes. Instead of having fun in the sun, she finds herself moving around in the shadows in search of answers. Her sleuthing entails hunting out a secret subterranean office, hacking into emails, sifting layers of deceit, creating “digital deflections” to cover the tracks of a missing person and evaluating whether one character’s dirty deeds could extend to murder. She looks for the truth while hiding behind a false front. But are those around her who they claim they are?

Ritter’s second novel is a fiendish tale of trouble in paradise. Co-written by Lindsay Jamieson, it boasts several strengths: It is expertly paced, tightly plotted and, in places, genuinely gripping. However, “Retreat” has its flaws. It is laced with the requisite twists and turns we expect from this genre, but one big reveal is so big that we see it coming. On occasion the prose is marred by groan-inducing clichés, particularly when it attempts to stoke tension (“My heart pounds; my breath races”) or convey romance (“I let myself get lost in Jay’s dark eyes for a moment”).

However, we forget about faults during the book’s many absorbing episodes. Ritter routinely ramps up the intrigue and drama, such as in one taut scene where Liz scrolls through someone’s phone for clues — and is forced to think on the spot when caught in the act. Ritter also excels with sharp lines about, and acute observations of, the gilded worlds and charmed existences of the privileged elite (a Yale graduate showcases “the naive pride of someone winning at life when they started at the finish line”).

Best of all is the novel’s main character. Liz is a compelling creation, at once smart, sassy and wily, and there is fun to be had watching her slickly outwit credulous individuals. “You’re different from all the other women here. You’re real,” one unsuspecting lady of leisure tells her. It is equally rewarding seeing Liz flounder as she gets more and more out of her depth. “I’m Cinderella after the ball,” she says at one point, “and the spell is wearing off.” Ritter fleshes out Liz and shows more of her vulnerable side through flashbacks to the hard knocks she experienced in her emotionally turbulent past. We come to champion her as the streamlined narrative hurtles toward its shock finale.

Readers who don’t make it that far will no doubt bewail the novel’s unlikely premise and other stumbling-block implausibilities. But it pays just to sit back, suspend disbelief and enjoy the ride.