Professor Whitaker was a British scientist who proposed numerous controversial theories about time travel. He was hired by Charles Grover to design the Timescoop, a time machine which could transport people, animals and objects to and from different points in time. Using the Timescoop, he transported dinosaurs from the prehistoric era into the middle of modern day London, in the hopes of frightening everyone out of the city so that Operation Golden Age could commence.
When the Doctor found their underground base, Whitaker and his assistant Butler tried to kill him by transporting a pterodactyl into the tunnel with him, however he fought it off with a mop and escaped.
Although they removed all evidence of the entrance to the base in that particular area, Whitaker thought it prudent to try and discredit the Doctor. Whitaker called the Doctor at UNIT headquarters and feigned innocence, claiming he was held against his will by Grover and had escaped, telling the Doctor to meet him at a warehouse. When the Doctor arrived, Whitaker wasn't there. The Professor used the Timescoop to transport a stegosaurus into the warehouse, just as General Finch arrived with Brigadier Lethbridge-Stewart and some soldiers in tow.
Finch, who was in on the conspiracy, used the stegosaurus' presence to frame the Doctor as the one who'd been bringing the dinosaurs into the present, as per Whitaker's plan. However the Doctor was able to escape. Assisted by the Brigadier, he made it back to the Golden Age base and confronted Whitaker and Grover. Grover activated the Timescoop, transporting himself and Whitaker away to destination unknown.