Number Four (Battlestar Galactica)

Simon O'Neill Number Four
Battlestar Galactica character
First appearance	"The Farm"
Last appearance	Battlestar Galactica: The Plan
Portrayed by	Rick Worthy
Information
Species	Humanoid Cylon
Gender	Male
Affiliation	Cylon

Simon O'Neill (Number Four), is a fictional character, a Cylon from the reimagined Battlestar Galactica series. He first appears in The Farm (August 2005), an episode written by Carla Robinson and directed by Rod Hardy. Like the Cavils and Number Threes, and in contrast to Leobens, Dorals, Number Sixes, and Number Eights, Simons appear to be relatively uncommon and never appear in large groups. He has a more prominent role in the movie The Plan.

A Number Four first appears posing as a human physician treating Kara Thrace (Starbuck) for ballistic trauma in what was supposedly a hospital on Caprica. In reality, he was also performing invasive medical tests on her reproductive organs. After Starbuck begins to suspect the doctor's true nature, she kills him, and escapes from the facility. Her fears are confirmed when a second copy of the model greets her on her way. This copy is then gunned down by resistance fighters who rescue her. At least one other copy is seen on Cylon-occupied Caprica.

It is later revealed that a Number Four was the Caprica Buccaneers' team doctor and worked against the resistance by contaminating radiation meds and giving too much morpha. This copy was eliminated after Samuel Anders saw the Four copy who cornered Starbuck outside the Cylon facility

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