The Scorpion was an assassin hired by the Duke of Cardeas Sebastian from the planet Cicero Prime to assassinate his wife the Duchess Miranda. The Scorpion claimed that she always completed a mission and no target had ever escaped her before. She also claimed herself to be the "most feared assassin in the sector" and the deadliest in the Seven Systems.
She traveled to Cicero Prime in a Sting ship, a common ship for assassins as commented by theFifth Doctor. The Scorpion, as an assassin, was equipped with many gadgets to complete her jobs, including a Stasis field. (AUDIO: Kingdom of Lies)