Investigate Cersei

Ned began to have his suspicions of the King's beautiful bride. She was quite haughty, acting with nothing but scorn for the Northern party. Of course she was a Lannister, but there seemed something off, the way she glanced about as she walked, and her sly glances at lords' tables.

Ned began to observe her on the daily ride towards King's Landing. Cersei's mannerisms were odd. She was completely bored with the King, riding half asleep whenever she was with the King. More curious was her night habits, slipping out of her tent into the wilderness. Ned didn't follow her, he couldn't slip past the Kingsguard, but something was definitely off.