In Caemlyn she was put by forsaken under the leadership of Lady Shiaine. There Marillin met also Falion Bhoda that was in punishment by Shiaine for her failures. Marillin was ordered by Shiaine to find a way to infiltrate the Royal Palace. Marillin tells Shiaine that she cannot do what she wants, because the Palace is full of female channellers, but that there is a woman already in the Royal Palace who can.
Fortuitously she was later involved in the unsuccessful kidnap attempt on Elayne and so she was captured. When in Caemlyn she had heard about a woman Warder, but told nothing to the others.
In an attempt to interrogate a member of the Black Ajah, Elayne impersonates a Forsaken and in the process gets herself into a lot of trouble. Doilin Mellar, whom she believes to be a Queen's man but is really a Darkfriend, assaults her. Timely intervention by Matrim Cauthon and Birgitte Silverbow saves Elayne from further harm, but Mellar escapes.
During the fight between Elayne and Mellar, Marillin and Falion were probably freed from the dungeons by Jaq Lounalt.