While potholing under Wenley Moor, he made first contact with the Silurians, and wanted to keep the scientific glory of his discovery for himself. He told only his assistant, Phyllis Dawson, of his find.
When UNIT arrived at the facility and began searching the caves, Dawson began to worry, but Quinn reassured her. Quinn decided to contact the Silurians again. When he arrived, the leader told Quinn to find the Silurian that Major Baker wounded. The leader gave Quinn the Silurian's summoning device.
Quinn searched for the Silurian and began to obstruct the Third Doctor's investigations. Searching the countryside, he managed to find the Silurian before UNIT did. He brought it to his cottage and planned to hold it captive, and force the Silurian to give him the scientific knowledge they promised him. Despite Miss Dawson's warnings, the Silurian Dr Quinn was holding captive killed him. (TV: Doctor Who and the Silurians)
Behind the scenes
- In the novelisation, Quinn's first name is Matthew.