Combining elements from several ancient Greek myths, the story revolves around Perseus (Harry Hamlin), a young man on a quest to find himself and save his love, defeating a rogue’s gallery of villains along the way.  Throughout his quest, Perseus meets up with many gods and mortals, including Ammon (Burgess Meredith), a playwright who becomes a mentor to the young hero.  While talking with Ammon, Perseus discovers three gifts that he is given by the gods: a cloak which makes him invisible, and an incredibly powerful sword and shield, both made of a highly reflective, unusual metal.  He finds Pegasus, the legendary winged horse, and has everything he needs to begin the adventure.  Perseus meets Andromeda (Judi Bowker), a princess, and instantly falls for her.  One night, he sees her being carried off by an enormous vulture, which he follows to the lair of Calibos (unusually, played by Neil McCarthy when he has dialogue, but animated by Harryhausen when he has to fight), Andromeda’s former love.  Calibos, son of the goddess Thetis (Maggie Smith) was to marry Andromeda until he was turned into a beast by Zeus (Sir Laurence Olivier) for hunting a herd of winged horses – killing all but Pegasus.  Andromeda’s suitors must now answer a riddle of Calibos’s choosing before they can marry the princess.  Perseus, using his invisible cloak, overhears the riddle, and Andromeda is returned to her bedroom.  Calibos discovers Perseus’s footprints appearing in the swampy marsh, however, and they fight.  During the struggle, Perseus cuts off Calibos’s hand and makes his escape on Pegasus.  The time comes, and Andromeda presents the riddle to her suitors.  Perseus is the only one who knows the answer, and they are set to be married.  When the queen compares Andromeda’s beauty to that of Thetis, the goddess appears and demands that the princess be offered as a sacrifice to the Kraken, an enormous sea creature known as the last of the titans.  In order to save her, Perseus must stop the Kraken by getting it to look at the decapitated head of Medusa, a half-woman, half-snake creature whose gaze instantly turns those who look upon her into stone.  Before he takes off to find the creature, he rounds up a small band of men.  He also gets the aid of a small mechanical owl named Bubo – another gift sent down by Zeus to even out the helmet he lost in during his first expedition to Calibos’s swamp.  On his way to slay Medusa, Perseus must travel the very edge of the underworld.  Once there, he battles Dioskilos, a two-headed dog.  Defeating it, the men make their way to the ruins where Medusa is lurking.  Medusa, arguably the most frightening creature Ray Harryhausen has ever brought to screen, kills two of his men, one by her bow and arrow, the other is turned into stone.  Seeing her reflection in his shield, he turns and cuts off her head with one blow.  He takes the head with him and makes his way back to save Andromeda.  Before he reaches her, however, Calibos returns and – spying the sack containing the head, stabs it, spilling her blood and releasing scorpions, which grow to enormous sizes and fight with the heroes, all of whom are slaughtered, the exception being Perseus, who destroys the creatures.  Perseus finally slays Calibos and continues on towards the princess.  When he arrives, she is chained to a rock.  The mighty Kraken rises from the sea, but is finally defeated when Perseus flies in on Pegasus.  The Kraken sees the head of Medusa, which Perseus takes from his satchel, and turns into stone.  The princess is saved, Perseus’s quest has ended, and the two shall be wed.

Creatures to look out for:

Trivia:

• The 16 Million budget on this film exceeded the sum of all previous Schneer/Harryhausen collaborations.

• Arnold Schwarzenegger was suggested as Perseus as one point in pre-production.

• The Isle of the dead and the river Styx were filmed in Palinuro and a dried-up river bed near by.

• Janet Stevens, Steven Archer and Jim Danforth helped Ray in some of the animation sequences.

• It took Ray 16 months to complete the entire animation for the film.

• Clash of the Titans would be Ray's final film, although preparations for Force of the Trojans started in the end the project fell thru.