THERE’S no point in pretending otherwise: the plot in Deutschland 83 (C4, Sunday) is filled with irritating coincidences, and any niggling aspects which might derail the story are simply smoothed over. Consider Linda’s terrible death last week: when she was fleeing Martin why did she run into a scary German forest? This isn’t some American slasher movie where the breathless, beautiful girl always runs into the abandoned house or the darkened fairground.

Linda was safely out in the busy streets where no-one would have dared attack her but she chose to run into the eerie isolation of a forest, making it all too easy to be killed by a pursuer.

So why did she do that? The answer seems to be: just because. And, to make things easier still, her murderer just happened to be driving through the forest and was able to slam into her just as she entered the road. Why was he in the forest? Just because. And why was she in the forest? Just because, I suppose. Why was anyone in that forest except that it made the murder and the eventual disposal of the body easy and all rather dramatic and picturesque. That’s just shoddy.

There’s such a feeling of smoothing off the corners by throwing in coincidences and falling back on the playground principle of “just because”. And yet this drama is so good that we’re able to forgive the glaring and all too convenient coincidences, but I do hope the writers won’t rely too much on our goodwill and test our belief with yet more. Nonetheless I’ll keep watching … just because!

An unexpectedly good programme was to be found on BBC3, a channel I’m usually set to ignore because of its bouncy, youthful slant, but whenever I do poke around in its schedules I often find something good. Yes, every so often BBC3 elbows me in the ribs and says ‘See? We’re not just for young’uns.”

This week they impressed yet again with a powerful and achingly sad documentary called Murder Games: The Life and Death of Breck Bednar (BBC3, Tuesday). It was so devastating that I wondered why it had been relegated to BBC3, but it’s because the message is aimed at younger people – plus it gets an airing on BBC1 later next week, so all bases are covered.

Through painful interviews and dramatisations it told the sad story of Breck Bednar, a 14-year old boy who lived in the warm, secure heart of a loving family. They seemed quite well-off and Breck’s childhood was probably idyllic, with meals around a busy, talkative dining table, brilliant results at school, a happy circle of friends, and weekend adventures with the Air Cadets. It’d be hard to imagine a child more cherished, protected and set on the right path in life. What possible harm could come to such a boy?

But Breck was murdered, stabbed in the throat by Lewis Daynes in a sadistic sexual attack. Breck had met Daynes online whilst gaming, and the killer had slowly manipulated the younger boy who saw him as an older, glamorous figure thanks to Daynes’s lies about owning a computer company and flying off to New York for secret work assignments. Daynes spoke into Breck’s ear through his headphones, gradually dripping poison about his friends, his education and, most distressing of all, his mother.

Breck’s mother, Lorin, is a hero in this documentary. Devastated by her son’s terrible death, she cries openly on camera and says she stays alive only for her other children, but she also wants to campaign for online safety, hence this documentary about how Breck was groomed and killed.

Becoming concerned about his growing fascination with this invisible person, Lorin and Breck’s father tried to limit his time online, and eventually removed his computer altogether, in order to cut off Daynes’s influence. The killer responded by posting a mobile phone to Breck and so continuing to groom and lure him, and eventually arranging a meeting at his flat in Essex.

The dramatisations of Breck and Daynes’s online chats were lengthy and quite unnecessary as the most effective part of the show was the testimony from Breck’s horrified friends, his quietly grieving little sisters, his father who seemed in a state of shock, and Lorin, his brave mother, who did everything possible to keep her son safe but still couldn’t protect him when faced with the far-reaching tentacles of the online predator.

The internet makes all the old rules about child safety redundant: don’t talk to strange men, don’t accept lifts from strangers, don’t stay out late or go into the park at night. The rules we were all taught as youngsters don’t count for anything when we’re dealing with the virtual world. Your child, snug in his bedroom, can be in the company of anyone, from anywhere, and it’s brave women like Lorin who’ll help teach the new generation of children how to be safe.

STV lowered the tone by introducing a new series called Sugar Free Farm (STV, Tuesday). They get a bunch of celebrities and isolate them on a farm for two weeks where they’ll be forced to live without sugar. What a terrible idea! In an age when we’re all being warned about the link between our wild sugar consumption and diabetes and obesity, this series implies that cutting down on sugar is a crazy experiment which requires endurance and isolation, instead of being quite a simple adjustment. Cutting out the Irn Bru and the Rolos should do it, then gradually reducing the amount you stir into your tea and surrendering the nastier ready meals, and it’s done. It’s not difficult but daft shows like this imply that it is.