Alias's debut season is a master-stroke in story telling; where most shows take their time to get going (Agents Of Shield, we're looking at you), Alias knocked it out of the park from the first episode. The reveal that Sidney worked for an criminal organisation (SD6) posing as the CIA who murdered her fiancé and her dad is a double agent working for the real CIA? That's just episode one and as the season progressed, Sidney's double life allowed for some amazing drama, action sequences and even comedy. (Will discovering who Sidney is covers all three!) Yet, the show accelerated further with season two in no small part to the reveal of Sidney's supposedly dead mother. Established as a teacher killed in a car accident in the first season, deceased Laura Bristow was revealed to be the very much alive Irinia Derevko, a former KGB spy, confidant of series villain Arvin Sloan and the leader of the criminal organisation Sidney had been fighting against in both her SD6 and CIA guises. How does that first meeting go? Irina shoots her, of course! Though as we learn that is a ruse to save Sidney before turning herself in and establishing a relationship with her daughter by feeding her secrets about the enemy. It's a brilliant example of introducing a dead character that has a massive connection to the protagonist's life and flipping it on its head a hundred times over. Few characters have been brought back from the dead with as much style as Sidney Bristow's treacherous mother.