For close to a decade, twenty-five-year-old Felicity Lonsdale has masqueraded as a dowager almost twice her age--selling caterpillars to butterfly consortiums--enabling her to hide an ill-fated past while raising her late brother's daughters. Together, the three live on an isolated Irish estate bequeathed by a dying earl. When the earl's estranged son arrives to claim his inheritance by threatening to expose Felicity's true identity, she longs to pack up her nieces and run. But a ghostly secret within the castle's turret holds her captive.

Nick Thornton--a Roma viscount's heir--is also captive. After a tryst with an investor's wife nearly destroyed his family's holiday resort, Nick forsook everything to elope with her. However, a tragic mistake at his hand led to her and his baby's deaths. Refusing to turn to the family he shamed, Nick travels to seek the countess who once co-wrote a romance with his sister. There's rumor of a special butterfly in her keep--a transparent-winged species with ties to the afterlife. Nick hopes to contact his dead wife and child, for only their forgiveness can free him.

Upon his arrival to Felicity's estate, Nick offers to help her defeat the earl's son, on the condition she allow Nick to investigate her glass butterflies. Felicity agrees, though fears the closer he gets to the ghosts of his past, the closer he'll come to uncovering her own. As Nick spends time with Felicity and her nieces, he realizes the mystery enshrouding this fragile countess and her castle is more intriguing than the ghosts he originally came to find. And perhaps putting his dead to rest and helping her do the same will be his true path to redemption.