In a story that reflects the in-between spaces in our lives, Hillier's readable novel isn't some Sixth Sense ghost story, but it does feature people who are haunted--who are stuck, grieving, who can't seem to move forward but can't move back. A surprisingly character-driven, moody thriller, Little Secrets is ostensibly a detective story, a kidnap investigation led by main character Marin, the wealthy owner of a series of lucrative downtown salons. She's shopping in Seattle's Pike Place Market when she loses Sebastian, her young son. Suddenly he's nowhere near her, and she can't spot him anywhere. Marin's eyes dart, searching for any glimpse of her little boy with his dark hair so like her own.

The opening scenes are a gut-punch. The security cameras show Sebastian being spirited away from this touristy market by a Santa-like figure who perhaps promised him a treasured lollipop. Marin is left to cope with the grief and loss while reckoning with her husband, Derek's, anger. From the first panicked searching to the Amber Alert and the realization that Sebastian was deliberately kidnapped, Hillier captures Marin's interior life, the frantic calls which lead her back to nothing. As fog laces the air, Marin's only help comes from the fuzzy black-and-white security footage.

Fifteen months later, Marin pours her heart out in a local support group for parents of missing children. With no new leads, Marin's thoughts are "whispering, ominous clouds," a soundtrack she can't shut off. In desperation, she turns to her best friend, Sal. They go back a long way and Marin is thankful she still has one person in her life who doesn't feel the need to tiptoe around her precious feelings. Marin has also found solace in the routine of work. But life is now a series of slips and catches, a constant juggling act of pretending to feel okay when she wants to do is fall apart.

Hillier builds on the precise nature of Marin's pain, fear and dread, from her initial days of hope to her fractured marriage to Derek and Derek's own dalliance with a 24-year-old gold-digger college girl, Kenzie Li, who sees the wealthy couple as her ticket to fortune. Hillier's tale morphs into a cat-and-mouse game between Kenzie and Marin, as Marin begins to hatch a plan after being given incriminating information by her private investigator who Marin has kept on to keep searching for her beloved Sebastian. Classy on the surface, the investigator, Vanessa, is unafraid to get her hands dirty. Now Marin has the evidence: the restaurant photo and Derek's cell phone records. She wants to know everything that Vanessa has discovered.

The tension builds as Marin is plunged into an unfathomable underworld. While Vanessa reiterates that nobody in Marin's inner or outer circles was ever flagged as suspicious, Marin is enraged by Kenzie, suspicious of the younger woman's motivations. Visiting Kenzie at her coffee shop, the rage washes over her, "coating her outsides," forcing Marin into a world of shadow apps where denial is "a safe little bubble." Events turn dark when Sal hooks Marin up with nefarious money launderer Julian Black. An expensive fixer, ex-convict and casual drug dealer, Julian and shady bar owner Sal eventually set Marin on a course that will bring her full circle.

Guilt is Marin's default setting, coloring everything she thinks and feels and does. She feels the rage coming back, seeping through her pores. Derek is haunted and lonely, aching to talk to someone who isn't going to ask him anything about Sebastian. Kenzie's journey is to learn that when someone you love doesn't love you back, there are two directions you can go. Poor Sal is a "man-child," damaged by years of his father's abuse while stuck taking care of an equally damaged mother and in love with a woman who has never loved him back. Sal is the id to Marin's ego, the devil to her angel, the magnetic force that eventually steers her moral compass in the wrong direction.

Alternating between Marin and Kenzie's realities, there's no more avoiding or pretending in this story of a devoted mother and the missing son still in her heart. Sal holds dear to the possibility of a clue that might bring him closer to Marin, whose waterfall of hope for Sebastian connects her to the world, perhaps finally enabling her to mute the heartbreak until she can finally be reunited with her son.