The episode is set in what was the Mediterranean sea in 5 million years time. It features four species: (1) Cryptile, a lizard with a sticky frill to catch flies which it can then lick off at its leisure; (2) Scrofa, a descendant of the wild boar which has developed spindly legs to allow it to live on the rocky islands in the desert; (3) Gryken, a descendant of the pine marten which hunts Scrofa in the cracked rocks of the landscape; (4) brine flies (live-acted). Before this time in the future, the tip of Africa has collided with the southern tip of Spain, thus enclosing the Mediterranean inland. It has since dried up to become an enormous salt desert with a few lakes of ultra-saline water, as it was during the Messinian salinity crisis. The holiday islands that used to be in the sea are now mountains scattered throughout the desert.
