Jon Richardson is joining BBC school drama Waterloo Road as Darius Donovan, a teacher with charm but also an evil side. He follows in the footsteps of Jason Manford, who played headmaster Steve Savage in last year’s series. Earlier this year, Richardson revealed he had the role with a post announcing he was quitting stand-up to become a teacher – only revealing the truth 24 hours later…

What was it like tricking your fellow comedians and fans into believing you were actually becoming a teacher?

It was awful, because they were all really kind. They all totally fell for it, including Romesh Ranganathan and Laura Smyth [Both of whom used to be teachers. I’ve never had a more successful social media post. What was devastating about it, as well, is that not one person, and I had thousands, but not one said, ‘Don’t do it, stay in comedy, we need you.' They all said, ‘Good luck. Off you go, cheerio.’

Did you not warn anyone in advance?

It filmed quite close to home, so I was able to fit in a few panel shows and other things so I think everyone thought I was just carrying on as usual. The thing that made it was that at the last minute, somebody said, ‘Don’t do it on April Fool’s Day, because everyone will know it’s not real’, so we did it the day before, and that is what sent it stratospheric. My phone went absolutely crazy.

What made you want to be part of the series? How did you feel on your first day back at school?

I was nervous because it was all filmed in an actual school. I had all the anxiety you’d get being back at school, the smell of the canteen, the sound of boots in the corridors, and all that. But also, the nerves of coming into a big job like that. I was very lucky to, in my first acting job, be given something like Waterloo Road. It was an absolute gift.

Tell us about your character Darius Donovan…

Darius is what made me apply for the job. He’s an absolute monster, but he believes himself to be a charming, charming man who acts only in self-defence and has everyone’s best interests at heart. He’s an exceptional character to play. I’m very lucky but I hope I haven’t become him, and I hope they didn’t cast me because they think I’m like him.

How do the teachers respond to Darius when he arrives at the school?

To quote the phrase, men want to be him, and the women want to be with him. He’s found to be an attractive and charming breath of fresh air for the school. There’s an incident in his first episode where the existing staff must decide whether to trust him over a teacher who has been there a while and has just been nominated for an award, and somehow, he manages to convince them, so he’s obviously got some charm.

What kind of teacher is Darius?

I tried to make sure he looks competent as a teacher. I think for all the other stuff to be believable, you have to first and foremost believe that he is a teacher. The six formers wouldn’t be calling him Mr. Donovan, he’d say, ‘Call me Double D’ or something like that. I’d be one of those unbearable ones. He pulls a few favours, gets friends from the TV industry in to impress the kids. He’s very keen for the kids to speak highly of him, because he knows that will accelerate him up the ranks.

Did you draw from your own school days and any teachers that you had?

My school would have been closed down if there was anyone approaching Darius Donovan working there. As far as my days as a student go, I was terrified. My bag was so heavy because I used to carry every textbook with me in case, I got the timetable wrong. That meant that all a sixth former had to do was pull the back of my bag, and I would fall on my back like a little tortoise and get Stranded on the floor.

What was it like working with the other cast members, and did you know any of them prior to filming?

I knew Jason Manford, whose character, Steve Savage, was in prison by the time I joined the school, so we had a brief chat. Beyond that, I hadn’t met any of them, and that absolutely terrified me.

 I just assumed it would be a bit like stand-up comedy, there’d be a bit of wariness, and everyone would be trying to work each other out a little, but there was none of that. Everyone was instantly kind and generous, and helped me with anything I needed like the mechanics of filming. 

They never once made me feel like an outsider, despite the wealth of experience in the cast and some of the things they’d done. James Baxter [who plays deputy head teacher Joe Casey] was a godsend. 

I’ve made some friends for life, I hope. They might disagree, but whatever, they’re really going to be called my friends, whether they reply to me or not.

Can you tell us about any funny moments on set?

The one thing I am is a swot. I would learn my script, turn up on time, and I wouldn’t muck about on set because I hadn’t earned the right, but I’ll just say that James and Adam [Thomas who plays pupil Donte Charles]  have. 

They’re the worst kind of people for me to be around, because they can be doing silly voices and mucking around and being hilarious right up until the minute they yell ‘action’. Then, because of their skill, they’re able to immediately deliver a better performance than I could ever give, because they just know the job inside out, whereas I would need a couple of minutes to sort of get ready before a scene. 

They can be cartwheeling, throwing biscuits at people, then burst into tears and give the most amazing dramatic performance you’ve ever seen. Those two were a definite bad influence on me.

In your defence, you really couldn't go from having fun to being him, the evil in him is palpable…

Some of the hardest scenes were the staffroom scenes, because they’d take all day. You have every cast member in, so you’d have to reset the cameras for each line. In the downtime you’re all together and it’s very rare you’d get to all be together, so you’re having a good time, but none of the other actors knew what Darius had been up to, and I did… You’re sort of ashamed of yourself then in the green room, because you feel like you’ve lied to everyone. It’s hard to look people in the eye over your lunch!

Tell us about your school days. What were you like as a student? Did you have a favourite subject?

I did Spanish, French, and maths at A-level, which I think is quite an odd mix, but I really liked languages because I liked communicating, and I wanted to be able to go on holidays.

I liked maths because it was the only subject where you’d ever get told if you're right or wrong. I have to say, I hated school. I took it far too seriously and I wish I'd been naughtier.

Waterloo Road has always been known for broaching difficult topics on screen. Has the new series has been able to continue this?

This series is very intense. There’s addiction being dealt with, but also a death in this series.

It doesn’t get more serious than the death of a person due to a certain degree of negligence. Whether I work in acting again or not, I don’t think I’ll ever film stuff as intense as what we filmed in episode four. Ruth, the director we had for those episodes, was phenomenal. She came from a live background and has done a lot of theatre, and made those scenes feel like theatre.

How does Waterloo Road compare to your previous TV experience?

It’s incomparable. Jason Manford said to me that there’s very little that you’ve learned from stand-up that will be applicable here, and it was really good advice. 

I remember those first days of falling in love with stand-up. I could have done five gigs a night, every night for a year, and I never got tired of it because I was just learning so much. Every day on set and every scene was slightly different. It was unlike anything I’ve ever done, and it's completely addictive.

How do you think Waterloo Road reflects modern life in a school?

I hope Waterloo Road is nothing like the school my daughter will go to because there’s a lot going on…

I think TV series like Waterloo Road are a good way of dealing with real issues that affect people and drive conversations that we need to have. You do need to remember it is television, and it’s supposed to entertain, but you can’t underestimate how much work goes into scripting it carefully enough that it isn’t taken as real life.

If there is a Darius Donovan working in a school in this country, he needs to be found and stopped immediately

•  Waterloo Road returns on Tuesday September 23, with the whole series launching on BBC iPlayer at 6am, on BBC One, two episodes will air every Tuesday: one at  9pm with the second at 10.40pm.