Jed Mercurio's 'Line of Duty' grew, over the course of three series, from a fairly normal police corruption thriller into one of the best television series of recent years. 'Bodyguard', his latest effort, shows many of the same strengths and weaknesses. It's intelligent and absolutely gripping: the first episode in particular draws you immediately forward to the edge of your seat. It's also somewhat contrived. Of course, series about conspiracies are almost inevitably contrived, for that's what a conspiracy is - a contrivance - but too often, ordinary operational details occur a way that one feels fairly certain just wouldn't happen in real life. Meanwhile, the structure of the plot, centring on a lone hero, lacks the eventual strength of that of 'Line of Duty', where one came to care about a broad cast of characters with different, and often conflicting, interests. But I quibble; this is still a high-quality piece of popular entertainment, and a tense and absorbing watch.