Grisenko

Professor Grisenko was a Soviet scientist stationed on board a submarine. In 1983, he found the Ice Warrior Grand Marshal, Skaldak, who had been trapped in the ice below for 5,000 years. The Eleventh Doctor and Clara Oswald arrived on the submarine, although Grisenko didn't witness their sudden appearance. He bonded with Clara, comforting her when they found the mutilated bodies of two dead crew members and then shooting at Skaldak when the Ice Warrior grabbed her head. Skaldak then grabbed Grisenko instead but Clara begged him not to harm the scientist. The Doctor and Captain Zhukov arrived and Skaldak released Grisenko and returned to his armour before threatening to activate the submarine's nuclear missiles. Clara talked him out of it, pointing out that he had spared Grisenko and telling him that millions of innocent people would die if he went through with his plan. The submarine was then brought to the surface of the ocean by an Ice Warrior ship and Skaldak disarmed the missiles before leaving the Earth.

Personality
Professor Grisenko acted like a grandfather to Clara during their brief time together and was protective of her, as shown when he shot at Skaldak when he grabbed her head. Clara stated that Grisenko was funny, because he was somewhat eccentric and liked to sing in dangerous situations. When told about the possibilities of time travel his first question was to ask if his favourite band would split up in the future. He enjoyed Western pop music which he listened to on a Walkman, including Ultravox and Duran Duran.

Grisenko was griefstriken and horrified when he, the Doctor and Clara found two mutilated bodies and called Skaldak a monster. He tried to comfort Clara about this later.(TV: Cold War)