'Giant' by David H. Balkan and Luther Murdoch

Discovering that the oceans are inexplicably leaking away, the Foundation of Ocean Research sends the Cetacean crew to investigate. After finding a fissure in the ocean floor, Mark and his colleagues encounter a conman named Jack Muldoon, who offers to guide them through to the other side. They are unaware that a giant named Thark lives on the other side of the gap, whose gold mining is responsible for draining the water. Thark agrees to work with Mark to close the sluice gate – but Muldoon has other plans…

Patrick Duffy (Mark Harris), Belinda Montgomery (Doctor Elizabeth Merrill), Alan Fudge (C.W. Crawford), Robert Lussier (Brent), Richard Williams (Jomo), J. Victor Lopez (Chuey), Jean Marie Hon (Jane), Anson Downes (Allen), Carole Mallory (Vicki), Vicky Huxtable (Juliette Schubert), Sydney Lassick (Smith)

Directed by Harry Harris
Produced by Herman Miller

Executive Producer Herbert F. Solow

TX (US): 25th October 1977

Notes:
*Featuring Mark Harris, Doctor Elizabeth Merrill and C.W. Crawford