The Queen's Tower. Of Duty and Silver, #1

After 17 years locked in a tower for a crime she swears she didn't commit, Queen Merewyn might finally be released. She hopes that a visit by Nina, the queen of a neighboring country, will give her a chance for freedom, and a chance to help her son, Crown Prince Maxen, negotiate the treacherous waters of court politics. Nina's court sorceress, Daryna, however, resents the fact that Nina is focused on Merewyn's troubles, rather than concentrating on getting help from Merewyn's husband, King Ethelred, in modernizing their country.
Meanwhile, Merewyn's jailer and old friend, Duke Brandon, rushes to prepare his castle for the royal visit, knowing this may be his last chance to get the king and queen to reconcile. Initially excited when Ethelred finally allows her to attend the festivities, Merewyn begins to worry that some of the guests are plotting against her. Still locked in her tower, she prepares for the grand welcome feast and her first night of freedom in years, but every day brings ominous hints of a sinister conspiracy that might include the visitors, the church, her husband, and possibly even her beloved son.