In the Ultimate Universe, Dr. Igor Kragoff was a colleague of Sue and Johnny Storm's father. Reed Richards was invited to a scientific symposium but he was too wrapped up in another project to attend. Frustrated at his lack of attention, Sue decided to attend in his place, by herself.
While Sue was on route to Siberia, her plane was shot down by Kragoff's assistant, Sorba Rutskaya. Kragoff wanted to use Sue's DNA to resurrect Kragoff's wife. Unfortunately it would result in Sue losing her own life.
As the procedure was about to begin, Rutskaya betrayed Kragoff. She killed him, wanting Sue's power for herself. Rutskaya was caught in an explosion in the lab and was instead transformed into the Red Ghost. This resulted in one of the best cliffhanger endings for Sue Storm ever, as the new (Ultimate) Red Ghost grabbed Sue and scared the blonde girl like she has never been scared in her entire life!
Rutskaya can lay claim to having the two best Fantastic Four covers ever, where lovely Sue Storm is threatened by a female foe. Ultimate FF #49 has a real Gothic-like look to it, with the scary female Red Ghost about to close in on the blonde girl and Ultimate FF #48 has Rutskya grabbing Sue Storm around the neck in a power grip.