||The Doctor and Peri are startled to a see the
image of a girl fly through the TARDIS console room. They discover a time tunnel, and trace it
back to the planet Karfel, where they find that a cruel tyrant, the Borad, throws his opponents
into the time tunnel. The Doctor is forced by the Borad to retrieve the girl Vena, who fell into
the time tunnel with a vital amulet, and finds that the far end of the tunnel is in 19th century
Scotland! Bringing back Herbert, a young man holidaying in Scotland who enters the TARDIS
accidentally, and Vena, the Doctor must return to Karfel to defeat the Borad, who is revealed to
be a weird mutant!