As the foremost authority in temporal engineering, Kerensky believed he was working towards the goal of speeding up the maturing process of livestock, helping to feed the human race. He had no knowledge that his employer, Count Scarloni, was in fact an alien, nor that his experiments were designed to allow Scaroth to return to the past.
He was aged to death in an accelerated time field generated by equipment which he had designed for the Count. (TV: City of Death) Whilst to external viewers it passed in seconds, for Kerensky it lasted for decades, which he spent musing over his childhood, his scientific experiments and his work for the Count. (PROSE: City of Death)