Although New Tricks remains the best tv show of its kind, for the first time it shows signs of running out of steam in a series of two halves. The series starts with a conclusion to series 5's cliff-hanger in which Brian confronts his alcoholism. This excellent episode provides the traditional seemingly effortless mixture of mystery, comedy, believable characters and emotion. Sadly that proves to be the highlight of the first half as the next three episodes are of a lower standard than usual.
There's an X-files style investigation that has some amusing in-jokes, but which doesn't work, a downbeat and confusing investigation into a missing person, and an oddball and contrived story involving an old film. The main problem is the amendment to the format, presumably deliberate, that has worked well for 5 years that results in the characters' private lives being ignored. This has been gradually happening for a while, but now Sandra, Jack and Gerry no longer exist outside office hours and Brian only enjoys comic relief with Esther.
In addition, although it's understandable that in an episodic drama Brian's personal problems would be resolved and never mentioned again after being addressed in episode 1, the show has made story arcs work before. So this is lazy and removes the show's special feel, making it into a generic tv cop show. Adding to the problem is the introduction of serious political sub-plots and social commentary about migrant workers that feels out of place in a light-hearted show.
This is not to say the first half is poor, just that compared to the previous high standard the drop in quality is sad, but before it can become a trend the series picks up massively in the second half. Suddenly the characters have private lives again, leading to an excellent continuation to the long-running Ricky Hanson saga. By picking up on a story arc that started in the pilot episode while still providing a standalone tale that's entertaining even if you've not seen the show before, the makers demonstrate their excellent writing skills.
With the show back to its confident old form the final episodes have the usual mix of character and plot, private lives and public investigation. All the strengths are employed fully for the final episode which uncovers surprising revelations about two of the characters, one comic, one tragic, and both relevant to the story and excellently acted.
With the majority of the episodes being as good as ever, and the three that didn't work so well perhaps being one-off experiments with the format, there's no doubt that the series can run on for a while yet.