Dirk Gently, BBC Four

The great problem for holistic detective Dirk Gently is that he lives in a post-Moffat/Gattis-Sherlock era. How can any private investigator shine after the wit, intrigue, technology and bromance of that show? It helps that Gently, created by Douglas Adams, is a largely different beast: a picker-up of random threads, a believer that logic will never take you as far as chance. But he stands small in Sherlock's shadow.

The plots of this first episode of three were unlikely. A man was murdered after developing software which allows you to input the wished-for ending of a course of action then comes up with the irrefutable logic to justify it. (This had surprising and dark consequences at the end of the episode.) A woman thought her husband was having an affair and hired Gently (Stephen Mangan in his customary mad scientist role). In a cute twist, the husband thought his horoscopes were coming true and also hired Gently. The CIA got involved. Everything was related, as we discovered in the unengaging denouement.

TV shows are linear because the viewer expects a plot to develop

That was the key point for Gently: he repeatedly invoked "the web of interconnected events" for these cases because, as is suggested in I Heart Huckabees, he doesn't believe that chance occurrences are in fact chance. Because of this, there was a lovely exploration of determinism, causality and chaos theory in Dirk Gently. Not that it was phrased that way.

The problem with this expectation of randomness (or otherwise) is that it doesn't work properly in a TV show: TV shows are linear because the viewer expects a plot to develop. This is not like contemporary art, where contingency and direction can be thrown into the air, where you can explore an artwork from different perspectives and starting points. This is a shame, because a drama true to the spirit of Dirk Gently would be unlike anything we've seen on TV. It might be impossible, although with the digital proliferation it could happen. Dirk Gently is stuck between an admirable theoretical approach and a restrictive practice.

Dirk Gently, adapted by Howard Overman, struck out on a quite different path from Sherlock. Instead of Sherlock's dark scenes and brooding, it is bright, cheerful, surreal. Fellow Green Wing alumnus Darren Boyd played Dirk's hapless assistant Richard Macduff, the butt of several jokes (and violent assaults). Not everything was made to seem like a matter of life and death, even when it was, and by avoiding trying to ape Sherlock's hijinks and high drama it did not end up as Sherlock-lite.

And at least Dirk Gently asked interesting questions. Do we always start with our desires and produce the facts to suit them, rather than starting with facts? Is logic more important than intuition or even randomness? While Dirk Gently failed in the drama and comedy stakes, it was a much more thoughtful, indeed philosophical, programme than the slick Sherlock. I don't expect it will receive commensurate acclaim.