Upon Catelyn's arrival in King's Landing, she is brought to her childhood friend, Petyr ``Littlefinger'' Baelish, who identifies Tyrion Lannister, the dwarf brother of Cersei and Jaime, as the owner of the dagger used against Bran, and agrees to help Ned investigate the possibility of Lannister treason. During her return to Winterfell, Catelyn meets Tyrion by chance on the Kingsroad, arrests him, and takes him to her sister Lysa Arryn's stronghold in the Vale, where Tyrion demands trial by combat and regains his freedom when his champion, a mercenary named Bronn, is victorious.
Lannister
Catelyn