Peter Cushing and Doug McClure are Victorian inventors who make an earth boring machine. The first test goes wrong and they drill down to the centre of the earth where a humanoid race are enslaved by giant telepathic birds. They and a beautiful woman (Caroline Munro) are captured but they manage to escape and kill the birds. The plot is poor, the special effects are bad and the actors give the impression they know this is poor.
Peter Cushing
Doug McClure
Caroline Munro 
2/5