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During the destruction unleashed on the city of Caprica, Education Secretary Laura Roslin asks the captain of her starliner, Colonial Heavy 798 to contact the Ministry for Civil Defense to ask what they could do to help in the crisis.
The captain alerts Roslin to a successful communications link with someone on Caprica. Roslin speaks with Jack, presumed to be a government official as he is aware of key events that have occurred in the wake of the Cylon attack on the Colonies.
With that, the captain of the transport interrupts Roslin with news from Captain Lee Adama (flying escort in his father's old restored Viper) of a Cylon incoming missile. Jack is never heard from again in the miniseries, nor does Roslin speak again with any other surviving government officials. Later, Roslin is appointed to the office of the President of the Twelve Colonies by emergency succession (Miniseries, Night 1).
In an early draft of the miniseries, Jack is apparently another secretary in the Colonial government.