The Doctor, Ian, Barbara and Susan arrive in contemporary 1960s England, however due to a malfunction on the Tardis, they've all be shrunken to the size of ants.
Unaware of their now shrunken size, the travelers begin to explore the landscape. What they find are mostly dead insects, particularly ants. It's later discovered that the entire area has been treated with a new, experimental pesticide DN6, which has killed off the insect population.
At the same time, a government official named Mr. Farrow has discovered through his testing that DN6 is "too powerful" and kills off not only harmful insects but also helpful insects as well. Mr. Farrow intends to withhold his approval of DN6. The owner of the company behind DN6, Mr. Forester, murders Mr. Farrow and plans to alter Mr. Farrow's report and cover-up his murder, in hopes of retaining his investment in the pesticide.
The travelers get caught up in all this intrigue, and Barbara begins to get sickened after handling some grain seeds that have been treated by the pesticide. The Doctor, his sense of justice coming to the fore, intends to make sure that despite their small size, that Mr. Forester and his accomplice Mr. Smithers face justice for their crimes. The fact that The Doctor is willing to do this shows just how much The Doctor's own character has evolved from just a year ago in An Unearthly Child.
Planet of Giants was originally planned to be a four episode story, but the powers-that-be at the time decided that a shorter three episode story would make it more exciting. The current DVD includes both the aired three episode version along with a restored four episode version.
The three episode version works well, and I didn't feel like the story was edited or cut-down. I have yet to watch the four episode version, but perhaps after my marathon watch I'll revisit this story and sample the longer version.
Planet of Giants predates the American-made Land of the Giants by a few years, but it resembles that show in several ways, the oversized props and camera tricks to make us believe that The Doctor and his companions are actually ant sized. Considering the limited budget, the special effects work rather well.
The fact that the travelers are miniature sized adds to the peril and suspense. Cats, for example, suddenly become deadly simply due to their size. It's also appeals to one's sense for justice, as Mr. Forester and Mr. Smithers will end up facing justice for their murder of Mr. Farrow. A great opener to the second series/season of Doctor Who.
