He used connections to advance his subsequent career as a politician, and was eventually knighted. Following the death of Tobias Vaughn, Harrington-Smythe tried to buy International Electromatics without success. He then set up and became director of the Glasshouse.
Over the years, he gathered much information on UNIT classified operations. He planned to use it to destroy Lethbridge-Stewart's career, as his own military career was ruined.
Unknown to him, a former International Electromatics employee who had survived Cyberman modification had infiltrated the Glasshouse and exploited the institution. He kidnapped Harrington-Smythe to find out more about UNIT. Now aware of how he had been manipulated, Harrington-Smythe endured torture and died without revealing anything he knew. (PROSE: The Scales of Injustice)