Agatha Award nominee for Best First Novel

An "engaging cozy debut...will leave readers eager for the next installment." - Publishers Weekly

"O'Brien has written one of the most warm-hearted yet realistic cozies I’ve ever had the pleasure of reading."
Mystery Scene Magazine

​"Finding Sky has everything an astute reader could want in a woman-driven cozy: a plausible plot, a smart protagonist, sex appeal, and two adorable, if overactive, children." Mystery Scene Magazine

"Finding Sky was one of my favorite debuts of last year." BOLO Books

​"Nicki Valentine Mysteries are filled with the same type of wit, humor and intrigue that fans of Janet Evanovich's Stephanie Plum novels will love." - Arielle Deltoro, Living Life with Joy

​​​"Finding Sky is a book that has a heart and soul and the minute I started reading it, I knew it was something special...I can't wait to read more about Nicki and her journey as a single mom and modern-day Nancy Drew."
- Maggie Barbieri, Author of Maeve Conlon Novels and the Murder 101 Mystery Series

Praise for the Nicki Valentine Series

Sky High

Finding Sky

*** Part of every book sale goes to missing children's causes! ***

"Susan O'Brien once again mixes humor, layered characters, a bit of romance, and social issues into a seamless, riveting book. Write faster, Susan!" – Sherry Harris, Agatha Award-nominated author of the Sarah Winston Garage Sale Mystery Series 


​​Nicki Valentine Mysteries...No one gets on your case like mom.

"Written with suspense, sly humor, and sharp dialogue, this series only gets better with every new adventure showcasing this compassionate and thoroughly engaging heroine." – Kings River Life Magazine 

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"This breezy second outing (after the Agatha Award–nominated Finding Sky) features an enchanting amateur sleuth with dear friends and family who have her back at all times." – Library Journal

"O'Brien combines humor, wit, wisdom, and suspense in a captivating story involving a rookie PI struggling to balance the demands of crime solving and single motherhood. No cookie-cutter mystery here...Five stars plus!"

– Tracy Weber, Author of the Award-Winning Downward Dog Mystery Series

"I love this series. Even though this is just the second book, I feel like I am hooked for the long haul. It is so well written and the characters are so much fun that I just can't get enough." – Bookschellves

"A great, quick read. Suspense lovers who missed the first Nicki Valentine presentation will want to grab that one, as well, because this author has definitely brought forth a character that is a great one to follow." – Suspense Magazine