The Heart of a Mercenary by Loreth Anne White
I enjoyed Loreth Anne White's Letters to Ellie in the SEAL of My Dreams anthology enough that I decided to read her The Heart of a Mercenary (2010), one of the Shadow Soldiers series.
The story that weaves through the series involves saving the President of the United States, and, ultimately, humanity from a group seeking to control the world through the use of a terrifying biological weapon.
Sarah Burdett is the only survivor of a raid on the medical mission in the Congo. Before being killed, a physician hides Sarah and a set of samples from patients who died from a virus the likes of which he has never seen.
Hunter McBride, mercenary, knows exactly what is at stake when he's sent to recover the samples, yet he finds himself seeing Sarah as much more than an add-on to his mission. When the ultimate choice has to be made, will he save Sarah or humanity?
There's a lot of suspense and moving through the jungle while trying to avoid capture and certain death, and not much in the way of romance in this book. I found myself thinking, "Would you just kiss already?" That didn't happen until 75% of the way through my ebook, which I found a little disappointing.
To learn more about the Shadow Soldiers series, see the author's site here.
My overall personal rating of The Heart of a Mercenary is a B-.