'Homeland' is so over. Everyone pull a cry face

There are many other reasons Homeland has lost its way. For instance, it has stopped painting its characters in anything other than broad strokes of cheap matt paint, most notably in its strange decision to drop the most interesting aspect of Carrie Mathison’s character: she has bipolar disorder and secretly took medication to remain in her CIA job.

How does a drama go from being a complex, charged and expertly paced work to being a plot-shredded gurnathon? The answer seems to be because the writers never knew either their destination or how long it would take them to get there.

Actors are signed up for lengthy contracts of five years or so, without knowing whether they’ll get more than a few episodes, because many US shows must spend their earlier episodes in a limbo between success and cancellation.

Lost is perhaps the greatest example of this, with all those mysteries piled into the early episodes – the hatch, polar bear, miracles – even though the writers had absolutely no idea what they were going to do with them all until they went on a writers’ camp after the first season.

Likewise, Homeland’s writers set off into season one without knowing whether Brody would live or die by the end. Yet they had a nicely contained series, with a strong arc that touched down neatly in that final episode. They could have quit there. But television – and commerce – didn’t let them. Neither, it must be said, will the ratings. They continue to rise.

In this week’s episode there was a cameo from an actor, Chance Kelly, who had previously played a significant role in the Iraq war miniseries Generation Kill (made by The Wire’s David Simon and Ed Burns).

That did something quite rare in US terms: it made seven episodes and got out. It wasn’t cancelled. It didn’t run out of ideas. Instead, it set out to make a single season and didn’t change its mind halfway through or spin off into Generation Kill: Afghanistan.

If Homeland had ended after one season, and lived on in box sets and repeats only, it would have been near perfect. Instead it has developed into a cautionary tale about a show that has outlived its idea. It may have its ratings, but when it ends this week I’ll be one of the viewers pulling a cry face for all the wrong reasons.

@shanehegarty