A/N: Written for Throneland. Dany as a Lannister. The challenge was to write one of the canon characters as a member of one of the other great Houses.
Knowledge is power
Dany quickly slipped behind the tapestry just as the door to the storage room swung open. Peering out from her hiding place she witnessed her brother Jaime lean down and brush his lips tenderly against Cersei's forehead, and heard him murmur something that caused her older sister to laugh softly in response.
Dany had been following their movements for weeks now, ever since Cersei had angrily denied her younger sister's request to accompany Jaime to a tourney at Blackhaven. Cersei had been unable to go herself, and, characteristically, was not about to let Dany enjoy their brother's company if she could not.
Dany should never have expected anything else from her self-absorbed sister, but now that she had discovered the queen's dangerous secret perhaps Cersei would be more amenable to Dany's future demands
As much as she despised her older sibling, Dany was a true Lannister and would never betray those of her own blood or do anything to imperil their status. But she now had a powerful weapon at her disposal, and would not hesitate to use it to her advantage. Even Cersei, not to mention Jaime, cowered under the fearsome shadow of their sire, Lord Tywin Lannister.
Dany, her father's favorite child, had only to drop a hint of what she had observed to rouse their fear.
She had only to mention how disappointed their father would be by his children's indiscretions, by the risk they were taking.
A risk that threatened to destroy House Lannister, if it ever became known.
"You're such a quiet, passive little mouse, Dany," her sister had often told her with disparaging contempt. "You'll never get what you want if you don't have the ruthlessness to grab for it."
Sweet gentle Dany, always so pliant, so submissive, would finally show Cersei who was the true lion. Cunning, patient in stalking her prey, Dany would spring her trap, using her knowledge to wrest away Cersei's most valued possession and taking it for herself.
And there would be nothing that her dear sister could do to prevent it without destroying herself.