Jastrok

Grand Marshal Kastrok was the leader of a Silurian clan at Scafell.

Biography
Jastrok hibernated in the nest at Scafell and was known to the Third Doctor, who warned UNIT to be wary of him. In the 2010s, he awoke and planned to take over the United Kingdom; he had his warriors attack Kate Stewart, Petronella Osgood, Mike Yates and John Benton and took control of Anthony Burmaster, whom he used to sacrifice the Silurian farmers and scientists and fake his and his warriors' deaths. (AUDIO: Call to Arms)

To release and take control of Krelix's hybrid creatures, Jastrok had Burmaster board the Charybdis and gain access to a Sea Devil base. The breeding pens were breached and Jastrok left Burmaster to die. (AUDIO: Tidal Wave)

Jastrok sent Tryska to a Silurian research base in Greece to recover a fear trigger, a mission which was complicated by Kate, Osgood and Sam Bishop. He agreed to her suggestion that they destroy the research base in order to keep the information within from UNIT and was later contacted by Kalana, who found Tryska's corpse and brought him the damaged fear trigger. (AUDIO: Retrieval)

Having besieged Great Britain with Krelix's creatures, Jastrok marched on London and, in Westminster Abbey, told Mike Yates and Josh Carter to surrender. He made the Houses of Parliament his council chamber and declared the beginning of a New Silurian Epoch, but his plans were soon scuppered by Sam using a Lyme Industries weather station to make it snow. Kate arrested Jastrok as he hid behind the speaker's chair and froze him and Kalana beneath the Black Archive to await the Silurians' judgement. (AUDIO: United)

Personality
Jastrok was warlike and dismissive of the Silurian Triads, deeming them ineffectual. He believed that his people should be warriors and was willing to sacrifice his nest's farmers and scientists, (AUDIO: Call to Arms) as well as his Sea Devil cousins, as part of his plan to take over the United Kingdom. (AUDIO: Tidal Wave)