Sometimes when you’re watching an old show and visual effects technology has marched on, everything jars so much that you know something strange is about to happen. The Hardy Boys had, I imagine, a much, much greater budget than a 1971 episode of Doctor Who, and if they needed to film the actors in a room, Universal was perfectly capable of providing the room, whereas mocking up a kitchen for a single shot was a waste of the BBC’s resources, so the director elected to just blue-screen the actress into a photograph. So when Frank and Joe suddenly start walking around an environment that’s clearly not real, it’s because there are about to be special effects.
So “The Disappearing Floor” is dopey, but it’s charmingly of its time. It’s all about holograms, a science which the producers think is so unfamiliar to the audience of February 1977 that they explain it twice in consecutive scenes, and the last five minutes of the story is a one-line-after-another barrage of talk about the military applications of the missing professor’s new technology. There are even Russian agents. We are shown two of them in a car, ominously, and I said “These are the guys who say ‘blah blah blah secret plans, blah blah blah Third World War‘.”
Our son enjoyed this a lot, especially when Frank and Joe enter a room that’s been hologrammed to look like they’re outside in a forest with wolves. But he claims that his favorite part of the story was when they were in an underground passage and Joe says “Where are we, Transylvania?” At seven, he is the prime demographic for all the dumb jokes that Shaun Cassidy delivers.