Alias

Alias was a 2001 - 2006 American spy-action television series created by J. J. Abrams, which was broadcast on ABC. It stars Jennifer Garner as Sydney Bristow, a double-agent for the Central Intelligence Agency posing as an operative for SD-6, a worldwide criminal and espionage organization.

The Horizon (season 5 episode 9)
SYDNEY is kidnapped and drugged force to relive memories of places she has been and events she has seen.She manages to breakout but finds she is on a ship in the middle of the ocean.

Full Disclosure (season 3, episode 11)
Sydney learns the truth about her missing two years. She had been captured by The Covenant and they proceeded to brainwash her. Although, unbeknownst to them, she had been conditioned from a young age to resist brainwashing.