Maddy De Costa

 is a character on Treason. She is portrayed by Oona Chaplin.

Biography
Maddy is an ex-army officer who is now an occupational therapist working with veterans.

She is Adam Lawrence's second wife. She is devoted to him and is the stepmother of his two kids, Callum and Ella. Maddy wants answers when Adam's promotion to M16 chief jeopardizes their family, especially after discovering her husband has been in contact with his ex-lover, Kara Yerzova. She begins secretly monitoring Adam after her suspicions are roused.

While in the military, she served alongside Dede Alexander in Afghanistan. When the agency launches an investigation into her Maddy's husband, Adam Lawrence, Dede takes on the case to protect Maddy and use her as an asset.

Appearances

 * Treason