Lately I've been watching several TV series, and when I tweet about them or review them I often comment that the episodes feel or don't feel episodic. Here I'll attempt to explain what I mean by this. A series by definition is made up of episodes, but the episodes can cover a series story arc, or they can be stand alone episodes.
I much prefer series which deal solely with a main story arc, where each episode continues the unfinished business from the previous episode. Most series don't have a story arc big enough to fill a whole series, so each episode is a stand alone story which somehow contributes to the main story arc. I quite like these too.
My gripe is with series with no story arc, or where most episodes don't contribute to a main story arc. I feel these work only in a few instances, where the subject itself dictates that the stories should be short stand alones, such as in the case of police investigations or court cases.
Too many series with stand alone episodes (or as I call them episodic episodes) end up using a Deus ex Machina. These are defined by Wikipedia as:
"Deus ex Machina (Latin: "god out of the machine") is a plot device whereby a seemingly unsolvable problem is suddenly and abruptly solved with the contrived and unexpected intervention of some new event, character, ability, or object."
At best these episodes end up losing their suspense, because you know at the end something is always going to happen that will make the heroes win against all odds. At worse the episodes end up feeling contrived and full of illogical coincidences.
Take the ending of an episode of TV series Dark Angel as an example: Max, a genetically engineered super soldier argues with Zack, a genetically engineered super soldier with several cybernetic implants that he shouldn't kill Logan, a hacker. Zack cuffs Max to a pipe, and goes to Logan's penthouse.
Max frees herself, and phones Logan to warn him Zack is coming to kill him. Logan barely has time to get his things and call the elevator before Zack bursts through the skylight. The elevator takes Logan down to the car park, but Zack follows him and starts shooting. A guy with a bucket gets scared and falls, dropping soapy water on the floor.
Zack shoots Logan, but just as he's going to finish him off Max bursts in on her motorcycle and hits Zack who's gun falls on the spilt soapy water. Max and Zack fight, and in the end Zack throws Max onto the building's main electricity panel. He goes to pick his gun.
This scene feels contrived because everything happens exactly at the last second, like clockwork. When things look hopeless, by coincidence, we have Max on the floor near the building's main electricity panel and near but not in a pool of water, while Zack who has cybernetic implants is standing in the other end of the pool of water. You can imagine what happens...