Elizabeth, daughter of Henry VIII and Princess of England, has survived plots by Vidal Dhu, ruler of the Dark Sidhe, who wishes to have her killed because she will bring a long reign of peace, prosperity and happiness to England. Vidal would rather her sister Mary rule, because of the division, unhappiness and pain it would bring, that being the kind of energies that he and his court feed on.
Currently, King Edward, Elizabeth and Mary's sister, is on the throne, but he is sick and not long for this world. Northumberland, the regent for Edward while he is a child, wants to have someone he can control on the throne, which would be not Mary because she is too Catholic and England is now Protestant, and not Elizabeth because she is too intelligent and will not be ruled by him. So he schemes to have both sisters cut out of the succession and a girl of his choosing, Lady Jane Grey, to be put on the throne.
Both Mary and Elizabeth are living far from court, and Elizabeth is prevented from contacting Edward or seeing him. Elizabeth's protector and lover, Dennoriel of the Bright Sidhe, tells her not to go to Edward's sickbed for fear of her being imprisoned or killed by Northumberland. Elizabeth is saddened by this because she dearly loves her brother, but accedes to Denoriel's wish. When Northumberland does summon Elizabeth, Denno is sure it is a trap and holds her back from going. Mary almost falls victim to the same snare, because she wants to convert her brother back to Catholicism on his deathbed, but news that Northumberland's men are on their way to capture or kill her makes her flee with a few of her guards and ladies, and when Edward dies, she manages to come back and seize the throne from Lady Jane Grey, who eventually dies for treason.
Now Mary is queen, and Elizabeth must be doubly careful, for Mary has a little affection for Elizabeth, but believes her sister is a witch or enchantress. As well, Mary hates Elizabeth for the sake of their mothers. Anne Boleyn's marriage to Henry VIII made Mary into a bastard when her mother's marriage was declared invalid. That Elizabeth suffered the same fate after Anne Boleyn was beheaded and Henry married Jane Seymour moves her not a bit. In fact, Mary is jealous of Elizabeth's good looks and charisma, and her ability to attract people and devoted followers seemingly without effort.
Elizabeth is eventually invited to court solely so that Mary can keep an eye on her, but seeing how Elizabeth interacts with the other courtiers irks Mary to no end. Vidal Dhu, unable to attack Elizabeth directly by Oberon's decree, resolves to kill her by other means, and makes two men of the court into his spies and mouthpieces, constantly telling Mary that the only way she will sit secure on her throne is if Elizabeth is killed so she cannot act as a figurehead for a rebellion in her favor. Mary resists these whispers, alternately keeping Elizabeth close and sending her away.
Meanwhile, Underhill, Elizabeth runs into other problems. Since most humans Underhill are slaves, other Sidhe want to buy her from Denoriel for their own. One fat Sidhe in particular takes exception to the way Elizabeth fights back against the idea of his owning her, with her own magic, and she manages to freeze him. Before he can be taken care of, he disappears, and it is one of Vidal Dhu's spies that frees him and gets him to work on their behalf by promising him Elizabeth as a slave.
Elizabeth's cousin, Harry, hs been trying to clean out an evil-infested domain called Alhambra deep in faerie with several elder Sidhe looking for something to do with their time. By killing all the evil creatures several times over and doing the same with the constructs the evil had possessed, they manage to weaken and weary it to the point where most of the domain is free.
But Vidal Dhu, hearing reports of this evil, wants to recruit it to his side. He sends a weak Dark Sidhe to try and make a pact with it, but the spy manages to get possessed by it instead. It abandons Alhambra to live inside the spy, and Vidal finds it to be powerful, but rather simple in its evil. Vidal, once imprisoned by intelligent mists inside another domain, escaped by learning to control his anger. He was once like the Evil, but now finds it rather... simple, compared to his own way of reasoning and doing.
With Mary on the throne, the Dark court becomes more powerful than that of the Light, as the dark absorbs the sadness, hatred and discontent that Mary's reign is producing. Evil Sidhe and evil monsters roam Underhill, kidnapping humans and killing others in various domains. Elizabeth offers to use herself as bait, but neither Harry nor Denoriel will hear of it, even when she finds that one of the mischief makers is the fat Sidhe who attempted to capture her at a place called Furhold.
Meanwhile, in the human realm, Mary is negotiating to marry Prince Phillip of Spain, because they are both Catholic and because she wishes to honor her Spanish heritage. She also thinks that if she can birth a child, it would automatically remove Elizabeth from the succession, as any child of hers would take the throne before Elizabeth. After her marriage, she does seem to become pregnant, but in the end, she is not, and her body was only responding to her fervent desire for a child.
Elizabeth is recalled to court, and Prince Phillip is much taken with her, to Mary's displeasure. But he suggests to her that she must show Elizabeth only forgiveness and love, and all her problems will be over. Mary accedes to his wishes, even though she finds it very hard, but she really cannot bring herself to be successful at doing so, still hating Elizabeth inside.
When Phillip is recalled to the continent to fight, Mary sends him all the money and men she can. but he is ultimately unsuccessful, and she has nearly beggared the Kingdom for him, which causes more discontent and unhappiness. Mary is suprised and disheartened when she realizes how much the people hate her for what she has done, and that causes her to dislike Elizabeth all the more. A Catholic bishop spends a great deal of his time trying to get Elizabeth to confess that she is stirring up rebels against her sister, but Elizabeth denies it and manages to make it seem that the Bishop is being most cruel to her. Eventually, Mary's handmaiden Rhoslyn, another Sidhe who had been keeping Mary safe, gets the Bishop to remove the ring Vidal Dhu gave him, whereupon he becomes much less inimical to Elizabeth.
Finally, as Mary becomes older and less likely to bear children, Vidal Dhu convinces the Evil to impregnate Mary and possess her child, so that it may rule the country after she is gone and keep England mired in misery and grief. As Mary's personality begins to change, Rhoslyn must try to save her and the country from the fate about to be imposed on it. Can Elizabeth keep both England *and* Underhill safe from the forces trying to destroy them?
This is a very long book (over 600 pages), and covers years of time in the history of England. The real historical characters and the characters of the Sidhe who interact with them are intimately entwined so that the entire story seems real, even the parts that take place Underhill. The utter realness of the book makes you feel that this could be a true history, a true story, even if you know it isn't. The book is also incredibly compelling. You'll be hesitant to put it down because you'll want to know what happens next, even if you know your history of the time, as I do.
I really enjoyed reading this book, and the feeling of reality despite many of the characters being faeries or nonhumans. Elizabeth's love of live and zest for living, suppressed in the human world, come alive Underhill, both making her friends and enemies. But she has magic to aid her and allies dedicated to making sure she lives and comes to the throne. It is this magic that saves her from an assassin sent by Vidal Dhu (through intermediaries) so that he can remove her from the succession.
And although Elizabeth might have loved her sister, by the end, she can only feel pity for her, because her sister has beggared the realm, got good English men killed, and made the people unhappy and unsettled, all because of her faults and hatreds. Elizabeth also learns several lessons from Mary, although they are generally what not to do. She also gains a hatred of marriage and childbearing from the events of this novel.
I highly recommend this book, though you might want to read the rest of the series first, they being "This Sceptr'd Isle", "Ill Met by Moonlight" and "By Slanderous Tongues". This is a wonderful series and a wonderful book.