|Book(s)|| A Feast for Crows (appears)|
A Dance with Dragons (mentioned)
A Feast for Crows
Lambert approaches Queen Cersei at Lord Tywin Lannister's funeral and promises her the head of her brother, Tyrion. He wears a patch over his good right eye and swears he will not remove it till Tyrion is dead. Ser Jaime Lannister spots Lambert riding at a quintain in the yard of the Red Keep. Lambert is often seen in the court of Queen Margaery according to Taena of Myr.
During his torture, the Blue Bard is forced to list those he claims to have been Queen Margaery Tyrell's secret lovers, among them Lambert's. Cersei has an arrest warrant signed for Lambert as part of her plans to remove Margaery. He is sent to the dungeons after his arrest.
A Dance with Dragons
Lambert is held with the rest of Margaery's falsely accused lovers in a dungeon under the charge of Qyburn.