Ray Harryhausen has provided the special effects for many movies, some of them quite good. In Clash of the Titans, however, one gets the feeling that instead of the special effects being used to dramatize the story, the story is guided by the desire to display some special effects. The result is rather lackluster. The story in the movie, however, such as it is, is a big improvement over the original myth. In fact, this movie, when compared to the source material, provides an excellent example of the need to modify ancient tales in order to make them suitable for modern audiences.
As for the story in the movie, much is driven by the lunacy of the gods. When the unmarried Danaë (Vida Taylor) has a child (Perseus) out of wedlock, her father, King Acrisius (Donald Houston), feels that he and all of Argos have been dishonored by her sin. He is especially put out by the fact that he had locked her in a room where no man could get at her beautiful body, but she got pregnant anyway. (In the original myth, Danaë’s son was destined to kill Acrisius, which was his motive for trying to keep her away from men, but in the movie, Acrisius is simply jealous of her beauty.) To purge the dishonor, he condemns his daughter and her child to die in a coffin set adrift at sea. Zeus (Laurence Olivier), it turns out, was the father, having visited Danaë as a shower of gold. Zeus is horrified that Acrisius of Argos would commit a murder, so to punish him, he has Poseidon (Jack Gwillem) unleash the Kraken, a sea monster, to wipe out the entire city of Argos. At the same time, Danaë and Perseus are saved.
When he grows up, Perseus (Harry Hamlin) falls in love with Andromeda (Judi Bowker), who is under the spell of Calibos (Neil McCarthy), the hideously disfigured son of Thetis (Maggie Smith). Perseus chops off the hand of Calibos, who then begs his mother for justice. She is reluctant, because she suspects her son wants revenge rather than justice. But when Queen Cassiopeia (Siân Phillips), the mother of Andromeda, dares to claim that her daughter is more beautiful than Thetis herself, that is just too much. As punishment for insulting her beauty, she demands that Andromeda be sacrificed to the Kraken. Almost as an afterthought, she says that this will give her son justice too. So, Andromeda must be punished for what Perseus did to Calibos as well as for a remark made by her mother, a remark, by the way, which happens to be spot on. A running theme through all this is that guilt and punishment are not individual matters; instead, punishment may fall on anyone who is associated with the person who committed the misdeed. Unfortunately, this insane notion of justice is frequently found in the myths of ancient religions, and there are still vestiges of such even today.
Anyway, Perseus has to figure out a way to kill the Kraken and save his beloved Andromeda. After much to do, he learns that he must obtain the head of Medusa, a gorgon whose look will turn any living creature to stone. Perseus chops off her head and returns in time to let the Kraken get a good look at it, turning him to stone. Andromeda is saved, and she and Perseus marry and live happily ever after.
Now compare that with the original story. When Perseus set out to get the head of the Medusa, he didn’t know Andromeda from Adam. He just needed a wedding present for a king who was getting married. Perseus got the head, put it in a bag, and headed for home, hoping he would be in time for the nuptials. On the way there, he saw the beautiful, naked Andromeda tied to a rock, while being threatened by Cetus, the other name for the sea monster. He decided to save her, but first he made sure nothing happened to his wedding present by putting it behind some rocks for safekeeping. Then he killed Cetus with his sword. Having seen Andromeda naked, he just had to have her, so they got married. Then he grabbed the bag with the head in it and headed off for the wedding that started it all.
The story is vastly more complicated than that, especially since different versions stand in contradiction to one another. But the point is that the story in the movie is a definite improvement, and so much so, that it proves that we should not be terribly concerned with how faithful a movie is to the source material, so long as the movie is enjoyable. Unfortunately, Clash of the Titans, while an improvement over the original myth, is only fair.