Samantha Ryan is determined to work with a different partner at the Special Investigations Unit (SIU). She's put up with enough busywork from her partner, Gabriel Ryan, and her boss offers her the perfect solution- a chance to guard an official (one they suspect is actually a clone). Unfortunately, Gabriel is furious as he suspects it's a plot to draw out their enemy, Sethanon. Will Gabriel and Sam figure out how to handle the ever-growing connection between them in time?

PENUMBRA is the third and final book in the Spook Squad series. PENUMBRA is best appreciated in the context of the series as a whole as Keri Arthur plunges the reader headlong into the phenomenal world she has crafted. The ongoing storylines as well as the relationship between Gabriel and Sam have been developed over the course of the series.

Arthur PENUMBRA is action packed, from start to finish. Keri takes us further into the mystery of Sam's past and the connection to the Hopeworth Military Base. I love seeing Sam continue to grow and develop confidence in herself as she starts to look at herself as more than just the job.

Keri Arthur is a master at urban fantasy world building and character development and the Spook Squad series is proof of this. I've read and reread this series and love it each and every time. My only disappointment with PENUMBRA is that the series ends here as there are no plans to continue it. PENUMBRA and the Spook Squad series are masterfully done and I can't recommend them enough!