White Knight — Kate Harper

Merrick St Arnould, an earl in waiting, does not believe in love. In truth, he is inclined to believe marriage itself is a dreary hoax dreamed up to nail a young man down in the prime of his life. With his two best friends - St Giles and St Severn - he enters into a pact before leaving the hallowed halls of Oxford behind. Together, they swear to help each other approach the unpalatable business of marriage with cool common sense, for if there is one thing they are all well aware of, it is that losing one's heart is akin to losing one's sanity and is best avoided at all costs.
In the interests of serving his country - and annoying his father's peers - Merrick occasionally spies for England. It's an entertaining pastime, until he learns that his latest task is to track down and kill a woman who has ahead full of stolen secrets and the heart of a conniving schemer. Even so, Merrick has no stomach for killing a female but a traitor is... well, a traitor is unacceptable and he knows he must stop her from returning to France at all costs.
His resolution is unwavering, right up until he meets the beautiful Elena. Then he finds himself in a quandary, for how can he kill a woman whom he wants to protect from any ill-wind that blows her way? And, more to the point, who is going to protect Elena from his own reckless desire...