I just finished this book a few weeks ago: Dark Angels by Karleen Koen. I really got sucked into this one, I couldn't put it down, I also love the fact that it takes place in 17th century England. 

The long awaited prequel to Koen's beloved Through a Glass Darkly, Dark Angels is a feast of a novel that sparkels with all the passion, extravagence, danger, and scandal of seventeenth-century England. Unforgettable in dramatic force, here is a novel of love and politics, of romance and betrayal, of power and succession, and of a resourceful young woman who risks everything for pride and status in an era in which women were afforded little of either.

"Alice Verney is a young woman intent on schieving her dreams. Having left Restoration England in the midst of a messy scandal, she has been living in Louis XIV's Baroque, mannered France for two years. Now she is returning home to England and anxious to re-establish herself quickly. First, she will regain her former position as a maid of honor to Charles II's Queen. Then she will marry the most celebrated Duke of the Restoration, putting herself in a position to attain power she's only dreamed of. As a duchess, Alice will be able to make or break her friends and enemies at will.

But all is not as it seems in the rowdy, merry court of Charles II. Since the Restoration, old political alliances have fraye, and there are whispers that the King is moving forward to divorce his barren Queen, who some wouldn't mind seeing dead. But Alice, loyal only to a select few, is devoted to the queen and so sets out to discover who might be making sinister plans, and if her own father is one of them. When a member of the royal family dies unexpectedly, and poison is suspected, the stakes are raised. Alice steps up her efforts to find out who is and isn't true to the queen, learns of a shocking betrayals throughout the court, and meets a man that she may be falling in love with - and who will spoil all her plans. With the suspected arrival of a known poison-maker, the atmosphere in the court electrifies, and suddenly the saftey of the king himself seems uncertain. Secret plots are at play, and war is on the horizon - but will it be with the Dutch or the French? And has King Charles himself betrayed this country for greed?