Lost: Season 3, Episode 16
3 - 16: One of Us
Jack's joyous reunion with his fellow survivors is cut short when they realize that accompanying him is one of 'The Others,' and Claire is stricken by a mysterious, life-threatening illness.
Jack's joyous reunion with his fellow survivors is cut short when they realize that accompanying him is one of 'The Others,' and Claire is stricken by a mysterious, life-threatening illness.