Tired of being left to do all the heavy domestic lifting for the three kids while his wife is off pursuing her career, Joe has a brainwave: he buys a synth, Anita, a gorgeous, lifelike humanoid to help around the house. It's a normal thing to do in the parallel London world presented in Humans (Channel 4, Sunday), an eight-part sci-fi drama. Everything looks reassuringly familiar, but all the low-status, low-paid jobs – cleaning, looking after old people, punching train tickets – are done by humanoid robots.

To underline how ordinary it is, Laura (played by Katherine Parkinson, whom I'd watch in anything) initially responds with a very familiar "We don't need it, we can't afford it." But as the episode goes on she spends a lot of time staring at Anita's face, suspicious that her synth might be more human than she should be – and that's before she notices her husband (Tom Goodman-Hill) and her teenage son looking at Anita's backside.

Laura's instinct is right. Anita was captured from a band of similarly soulful synths who are on the run. Searching for them – at heart Humans, a British version of a hit Swedish series, is a thriller – are armed officials charged with eliminating any synth that is developing human feelings. That dangerous concept of singularity – the point at which machines become human – is explained with a great deal of clunky exposition.

This is probably maddeningly basic for sci-fi fans, as it has been the basis of just about every futuristic drama since Frankenstein, but for the rest of us – and Humans is a tense, appealing sci-fi lite drama – it's good scene-setting. And while Anita (the terrific Gemma Chan) is mesmerising, with her creepy emerald-green eyes, so too is the emotionally powerful side plot with William Hurt – Humans airs in the US later this month, hence the starry firepower – as a lonely old man whose synth, Odi, has been like a son to him but has now reached the end of its life and must be replaced by a more up-to-date version.

Number one toy

As I may have stepped on at least 100 Lego bricks, usually on the stairs in my bare feet, I have no trouble believing one of the headline statistics in

The Secret World of Lego

(Channel 4, Sunday): there are 100 pieces of Lego for every man, woman and child on the planet. And although I’ve cursed Lego pieces I’ve never regarded the bright plastic bricks in the darkish way I do now, having watched this superb documentary.

Lego is the world’s number-one toy, but there’s nothing playful about how secretive the Danish superbrand is. It’s an intense secrecy, gleefully noted at every turn in this film, where closed-off sections of the Bilund HQ and the carefully crafted corporate-speak are highlighted; brick walls are the obvious analogy.

The weirdest scene is when, rather than let the camera in on a product-design meeting, the team re-enact one that happened months ago. The programme-makers don't go along with the deception, telling us that it's a set-up (Hugh Bonneville is the plummy, sardonic narrator).

Everyone at Lego is on-message all of the time: employees must “love the values of Lego”; they must have “the Lego DNA”; a very smiley woman answers that, no, it’s not a cult, “it’s like a family” – an expression that always causes a shudder when used in any work environment.

It's heart-warming to see sweet, open 23-year-old Justin get the job of his boyhood dreams as a Lego designer. (He has multiple interviewers and then a group workshop at Lego HQ that involves playing with other candidates.) But it's less lovely to meet him six months into the job and to hear the rote answers he gives to questions about what he's working on. It's not an audition for Humans, but it's a close call.

And if you’re an Aflo (or adult fan of Lego: it’s a thing, apparently) with a great idea for a new range that the company puts into mass production – like Jim, who hit on an idea for Lego bird kits – your royalty fee from the most profitable toy company in the world is a measly 1 per cent. We are reminded, often by Lego employees, that it’s a company that doesn’t “focus on money”. Given its profits – it’s a family firm and doesn’t have to reveal how much it makes – that’s a bit much to take.

Is all this fair on Lego, though? Isn’t it the nature of the corporate world for companies to be secretive, for employees to be permanently on-message? Maybe it’s childish to assume that just because a company makes toys it’ll want to play.

The series A Legacy (RTÉ One, Tuesday) kicks off with a profile of the late Brian Lenihan. The obvious question is, why now? The film is beautifully edited, with moving archive footage, but it is a jarring mix of the incomplete personal (his aunt, brother, sister and employees talk but not his wife or adult children) and the incomplete political (is it really possible to assess the life's work of the former minister for finance when the facts of the banking crisis and the bailout are still not fully known?).

One of the key figures in his life at the end was his boss, Brian Cowen, who is notably absent here. Legacy-type lookbacks require some distance to get perspective, especially when there is the emotive element of man dying so relatively young, a sad reality that understandably tempers his friends' and colleagues' remarks. A truly unafraid profile of the man would have included a cool psychological perspective on why he, as a dying man, ran for election and for leader of the party.

Fanboy delight

What’s lovely about

Dara Ó

Briain Meets Stephen Hawking

(BBC Two, Tuesday) is the Irish comedian’s fanboy delight in meeting one of his heroes. It’s an intimate portrayal – there are interviews with two of Hawking’s children and some of his many assistants – jarringly mixed with typically bland interviews with the stars of the Hawking biopic

The Theory of Everything

, all underscored with a syrupy soundtrack.

But Ó Briain is clearly in awe, and it’s catching. There’s no time for small talk in Hawking’s world – for practical reasons it’s too exhausting – but even the brief interviews elicit provocative nuggets, including his opinion on assisted suicide: “To keep someone alive against their wishes is the ultimate indignity.”

tvreview@irishtimes.com