Outside the Lines: An Isla Rivers FBI Suspense Thriller, Book 3

Isla Rivers #3

by Blake Pierce, Vicki-Jo Eva (Narrator)

When Lake Superior's serene surface belies a deadly pattern, only FBI Agent Isla Rivers sees the ripples of murder among the so-called accidents. In a city where the line between nature's wrath and human cruelty is blurred, Isla must piece together a puzzle submerged in dark waters.

OUTSIDE THE LINES is the third book in a long-anticipated new series by #1 bestseller and USA Today bestselling author Blake Pierce, whose bestseller Once Gone (a free download) has received over 7,000 five star ratings and reviews. The series begins with OUTSIDE THE ROOM (book #1).

The Isla Rivers series is a riveting mystery series brimming with suspenseful cat-and-mouse dynamics and unexpected turns that will send shivers down your spine. Its enthralling female lead will capture your affections and keep you engrossed in the story long after you turn out the lights. Fans of Lisa Regan, Lee Child, and Mary Burton are sure to fall in love.

Future books in the series are also available!

Audible Audio

Published December 16, 2025

About the author

Blake Pierce is author of the bestselling RILEY PAGE mystery series, which includes seven books (and counting). Blake Pierce is also the author of the MACKENZIE WHITE mystery series, comprising four books (and counting); of the AVERY BLACK mystery series, comprising four books (and counting); and of the new KERI LOCKE mystery series.

An avid reader and lifelong fan of the mystery and thriller genres, Blake loves to hear from you, so please feel free to visit www.blakepierceauthor.com to learn more and stay in touch.

Reviews

[Amy · Rating 3 out of 5]

By the third book, this series really finds its rhythm. The stakes feel higher, the tension tighter, and the emotional weight a little heavier. I was pulled in quickly and stayed locked in the whole way through.

Isla continues to evolve in ways that make her feel more human and layered. The pressure she faces is intense, and I liked seeing how her instincts and experience shape the choices she makes. The suspense builds steadily, with enough twists to keep things interesting without feeling chaotic.

There is a darker tone in this installment that adds depth to the story. It feels more personal, which made certain moments land harder for me.

Overall, this was another strong entry in the series. It keeps the momentum going while giving the characters room to grow, and I am definitely invested in seeing where things go next.

[D · Rating 3 out of 5]

Somewhat repetitive storyline, and the same descriptions are often used within the same book (for example, a seagull landing and taking off was used twice, in exactly the same way.)

The professional / personal development between the characters is lacking, so their mutual arc isn’t very believable.

Overall it is easy, comfortable reading if you forgive all the shortfalls that come with pumping out books at a breakneck speed. I’m enjoying the series.

[Laura Poppenwimer · Rating 3 out of 5]

Not the best in this series, but the plot was rather interesting. The characters seem lacking in some places and well defined in others. The descriptions could be more detailed, but overall not a bad book. Good enough to keep reading the series.

[EJ Breu · Rating 5 out of 5]

I’ve listened to books 1, 2, and 3 in two weeks. I may actually have to read a book as the next books aren’t available on audiobook! Great series. The characters are developing well.

[Suzie Dupree · Rating 3 out of 5]

I listened to this as an audio book. I didn't like that they chose a British narrator when the setting was in the Mid-West, USA.
The story was good though.