IT was supposed to be a one-off, but kids' telly hit Nina and the Neurons is now back for its seventh season on the box.
And its Scots star Katrina Bryan believes the sky's the limit for the future.
"Children are so curious about everything. There are endless possibilities for where we could go next," she says.
"Nina in space? I like the sound of that..."
The 32-year-old has become the darling of CBeebies, the BBC's channel for three to six-year-olds, since she first "heard the beep and saw the flash" on the science show.
She plays smiley scientist Nina, who takes questions from kids and then sets about answering them through experiments and investigations with the help of a collection of animated Neurons, voiced by actors including Sharon Small and Siobhan Redmond.
Since the first run, which tackled science and the senses, Nina has investigated the environment in Go Eco, looked at basic anatomy in Brilliant Bodies and had fun Inventing.
The new series kicks off on January 14 and this time, Nina and the Neurons Go Engineering.
"We got to visit some amazing places, such as Cruachan Power Station, in Argyll, which is like some kind of huge Bond villain lair in a mountain," she laughs.
"We went to an aeroplane museum to find out how things fly, tested out Europe's largest glass floor at the Spinnaker Tower in Portsmouth and got to open and close the Thames Barrier, which was great."
She adds: "Children love learning how things work. They are like little sponges at that age, too.
"I think each series of Nina has become more ambitious and the team of educational researchers are great at answering big questions in a way that young children will understand.
"The show tackles the kind of questions parents get stumped by all the time – like how is electricity made?"
Katrina is used to being stopped in the street by fans.
"It's usually parents who recognise me, but I do get asked lots of questions by children once they realise who I am," she smiles. "Lots and lots of questions. I always say 'well, I think that's an excellent question, and you and your mum should go off and do some research to find the answer...'"
She giggles. "People ARE disappointed sometimes when they realise I'm not a real scientist.
"I wasn't even that good at science at school. I loved biology but my brain didn't really work that way.
"It's funny though, because since I started doing Nina, I realise science isn't just about fancy formulas and complicated equations, it's all around us in every-day stuff."
Katrina is appearing in panto in Canterbury, Kent, and also starred in CBeebies own panto, Jack and the Beanstalk, on December 21.
"I love panto – I love the whole atmosphere and the way you have to just go with the flow and react to the audience," she says.
"I didn't fall in love with it until I was at college studying drama, though. Growing up in Gatehouse of Fleet, which is a small place in Dumfries and Galloway, the nearest theatre was a wee while away. But I like to sing, I can dance a bit, so I thought I'd give it a go."
Katrina loved performing when she was younger – her first big stage role was as Joseph in the Amazing Technicolor Dreamcoat – but didn't fancy drama school.
"I just never thought stage school could be a place for someone like me," she recalls.
"When I saw the advert for an acting degree at Queen Margaret College in Edinburgh, I thought that sounded much more up my street.
"And lots of my friends were going to the college to do different courses, so it made sense."
She adds: "I've always been realistic about acting – I remember sitting with my parents in the car and saying 'now, I might be out of work for quite a while...'. I worked in Accessorize after I left college, in between going for auditions.
"I was lucky to get work fairly quickly on stage and screen."
Katrina has appeared on Taggart and BBC paranormal drama Sea of Souls, but it is as bubbly, bunches-sporting Nina that she is best known.
"I only get recognised when I have my bunches in," she grins.
"I'm wearing them just now, actually, as I'm playing the good fairy in Sleeping Beauty, so I have them on stage.
"I don't wander about with them in all the time but I have, on occasion, left the theatre in a rush between shows, and realised halfway down the street I'm still wearing them."
She adds, with a giggle: "Not a good look for a grown woman. And it starts to hurt after a while."
l Nina And The Neurons Go Engineering starts on CBeebies on Monday, January 14.