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Film Appreciation... Twyman's Lock and Dam Theory of Plot Development



Over the years I have developed a theory about how plots and action develop in most films. The best way to explain it is to look at a typical canal system (you know like with locks and dams). Essentially, a canal works like this the boat enters the canal at one end, the dike or wall raises up behind it, and water is then pumped into the holding area effectively raising the boat up to the next level, whereupon the process starts over again. Films function in much the same manner, they open up with an incident that captures the audiences attention and (if they are functioning properly), then slowly increase the tension (via a series of episodes or incidents), until the film reaches its conclusion. Just like a canal system action does not increase in a straight arc instead it increases in stages. Generally speaking, each of these stages is followed by some sort of comic relief (a tension breaker - or pause), before the next episode and increase in tension occurs.

So why do films utilize comic relief as a tension breaker? Why not simply move from one exciting event to another with no break in-between? There are any number of theories about this but my personal favorite is one I have lovingly christened the adrenaline factor. It works like this, back in the dimmer reaches of history our ancestors were confronted with numerous physical obstacles, trials and tribulations which they were unprepared to deal with. For example take your average Joe who is out foraging for food in the forest when he unexpectedly comes across a large (and extremely hungry) carnivore - one with excessively long fangs. What does our hero do? Under normal circumstances (barring the intervention of some higher power) he ends up as dinner. Enter the adrenal gland - natures little added shot of steam. The adrenal gland gives our average Joe a little more energy to run a little bit faster, or fight a little bit harder - in short it is natures way of making sure that Joe is capable of surviving. The problem is that when an audience is watching a film (at least a good one), it willingly suspends disbelief - in short the audience forgets that it is only a movie. As a result of this, the audience's adrenal gland is busy pumping out that shot of steam just like it would if there was a giant multifanged beastie hot on their trail. So what are their options? Well, they could always run laps around the theater (authors note: theater managers and other audience members tend to take a dim view of this), or they could pummel the person sitting next to them (theater managers and other audience members also tend to take a dim view of this). Many people sublimate this urge by hanging onto the person sitting next to them (this is particularly dangerous if you do not know the person sitting next to you). As a consequence, the prudent film maker inserts little tension breakers into the movie to give the audience a little time to calm down and to give the film maker an opportunity to set the audience up for the next scary sequence.

Probably the best example of a film that that follow this type of format is Steven Speilberg's classic monster epic "Jaws". The film is a textbook example of a cause and effect plot scenario from its opening inciting incident to its eventual dénouement. It also features some dandy little tension breakers.


1999 Debbie Twyman. All rights reserved. TERMS OF USE