Children of the Sun God, Book 4: Khentkaus A Novel of Ancient Egypt by Max Overton

Khentkaus has wanted to be king of Egypt since she was old enough to say so. Today she sits in the shade at the archery range, applauding her fourteen-year-old grandson. She tells him she is old and tired and wants nothing more than a cup of wine and a platter of honey cakes. If he should ever become king while he is still a boy, she says, his mother must rule for him. He laughs at the idea, but he promises.

Then his father, King Neferirkare, dies of poisoned wine on his dining-chamber floor. The boy keeps his promise, and his mother, who has no idea how to govern, lets her own mother decide for her.

The gods made Khentkaus a woman and filled her with the desire to rule, a vicious joke, she calls it. Now she is the real power behind a boy's throne. Controlling the king, she says, is almost as good as being the king.

Almost. In a year or two the boy will be old enough to rule alone. And the dead king's twin brother, Netjerirenre, knows exactly who poisoned that wine. She has had him stripped of his office. But the captain of the palace guard and the governor of the city have already promised him their support.

She has decided he must go. He has sworn to watch her die.