Barker was an agent for MI6 who was secretly working for the Russians.
Barker worked with a Russian spy who went by the alias of Miles Barrington Smythe. On 23 November 1963, Miles left secret documents for Barker which instructed him to use his government employee card to access information in William Pike's cab before being arrested by the police. Bill Pike was taken to a police station along with Jorjie Turner from 2050, due to her strange communications device. Barker questioned Bill as to why the Russian documents ended up in his cab. K9 Mark 2, Jorjie and Starkey rescued him because he was the great-grandfather of their friend Darius Pike.
Barker later met with Miles to discuss their close escape. (TV: The Cambridge Spy)
Behind the scenes
As Jorjie noted, Barker was identical to Thorne.
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