Hinks was a Global Chemicals employee. Primarily, he served as Jocelyn Stevens' chauffeur, but Stevens also used him for various illicit duties such as sabotage and murder. When Stevens learned that Jo Grant and Bert Pritchard were venturing down into the mine at the Llanfairfach Colliery, he sent Hinks to sabotage the lift so that Jo and Bert would be trapped once they went down.
In spite of Hinks' efforts, the Doctor and Dave Griffiths discovered the sabotage. Global Chemicals denied repair equipment to the colliery, claiming they didn't have it. So the Doctor and Dave went down into the mine after the trapped Joa and Bert themselves, although Bert was killed by the so-called "green death." Whilst down there, they discovered illegally-dumped toxic waste and the giant maggots it'd spawned.
When the Doctor broke into Global Chemicals with the aim of proving they'd lied and intentionally withheld the rescue equipment, Hinks and two guards attempted to apprehend him, but were quickly disarmed and defeated with Venusian Aikido. After this, when Stevens learned that the Doctor had recovered a maggot egg, he sent Hinks to the Nut Hatch to retrieve it.
Whilst breaking in, Hinks interrupted the newly-hatched maggot as it was about to attack an unsuspecting Jo, and was himself attacked instead and bitten on the hand. He thus became infected with the green death and presumably died later.