Lula comes to Tom's attention when she causes trouble for teachers and pupils alike, disrupting Denzil's commemorative ceremony and making hurtful remarks about Tariq's disability.
When Tom looks into the matter, however, he discovers that a sinister situation lies behind Lula's erratic behaviour: the youngster is terrified of her overbearing uncle Lionel, who believes she is possessed and plans to perform an exorcism on her…
Digital Spy recently chatted to Jason Done, who plays Tom, to hear more about the storyline and Waterloo Road's recent move to Scotland.
How well have you settled into Scotland?
"Well, it's been pretty uncanny, because the new school looks so similar to the old one. The original brief for the new building was 'the same but different', and it fits that completely. There are a few tweaks and changes because obviously it's a completely different building, but it does have a feel of the old school, so it really didn't seem alien or uncomfortable at all. Very quickly, it started to feel like we'd been here for a long time.
"I love the new location for the show, too. It's so pretty, because we have this wonderful backdrop with the mountains and the River Clyde, which is slightly more appealing on the eye than the M62!"
Did it take much consideration as to whether you wanted to stick with the show following the move?
"To be honest, yes. First of all, it's a big move to be so far away from home, so that was something that my family and I had to discuss to see if we could make it work. Of course, I also had to question how the move was going to be written, and whether it was going to be too far beyond the realms of plausibility or not.
"All of that was of course taken into consideration, but it was also exciting to have the opportunity to reinvent the programme, and to have this wonderful change of scene. I've previously worked in Glasgow on a show called Sea of Souls, but I didn't really know Scotland that well at all, so it was also a good opportunity to be somewhere else and to meet new people.
"Waterloo Road is very good at reinventing itself. With the turnover of teachers and pupils, it never stands still - and I think that's part of its charm."
Were you sad to say goodbye to the old Rochdale site after seven series?
"Oh yeah, absolutely. I'm not sure at the moment whether that old site has been demolished yet or not, but when I finish here, I will go back and visit it. I'm a little bit sentimental like that, as I've got so many fond memories of being there.
"Moreover, it was also sad because of the friendships that I'd built there over the years with a lot of the crew. There are a few familiar faces here with us in Scotland, but the majority haven't travelled with the show, so I do miss them. The crew here are absolutely fantastic but I've also got very, very fond memories of the people at the old place."
What can you tell us about the Lula plot in this week's episode?
"Well, you'll see that Lula seems to be behaving in a rather peculiar and disrespectful way. The rumours are that she is possessed in some way or that she could have some magical, mystical dark powers about her.
"Indeed, Lula's uncle calls her 'wicked', and she's even disruptive and disrespectful at Denzil's memorial service. Because of that, everyone is led to believe that there is something really wrong with this girl."
What happens next?
"Tom and Lula are drawn closer together by their own sense of loss and guilt. At this point, Tom is blaming himself for Denzil's death as he feels responsible for it. If he hadn't encouraged Denzil to get on that bus and have a look at this new school in Scotland, then he wouldn't have died.
"The parallel story with Lula is that she blames herself for calling an ambulance when her father was ill. Her dad was an illegal immigrant, and was sent back to Kinshasa after being treated in hospital. As he was in danger back home, Lula is convinced that he's dead.
"This goes some way to explaining her behaviour. It also transpires that she has been left in the hands of her wicked uncle, who wants to perform an exorcism on her through their pastor. So this episode is a pretty dark one, and it's a race against time for Tom to make sure nothing bad happens to Lula."
Do you enjoy being part of stories on Waterloo Road which really push the boundaries?
"Yeah, definitely. It's a funny show, because it can bounce from a very serious issue, to the absolute ridiculous! Again, I guess that must be part of its charm. I think that's the bonus of being involved in Waterloo Road - that it can go from one extreme to the other, and you get to play the whole spectrum of emotions."
Tom also struggles to give a good speech at Denzil's commemorative ceremony this week. Why is that?
"I just think he feels so wracked with guilt. He has a moment where he just feels that the whole gathering isn't really representative of Denzil. It's Tom at his most vulnerable, and he can't cope."
It sounds like Tom also has a tough time ahead as his son Josh wants to fly the nest. What can you tell us about that?
"Josh, as with all teenagers at that age, is striving for his own independence. Tom is being quite overbearing, though - he wants to be a great dad and take all of the responsibility away from Josh. That makes Josh feel very smothered.
"As a result, Josh wants to go away, make his own mistakes and learn from them. Eventually, Tom realises that if you love something, set it free."
What is Will Rush, who plays Josh, like to work with?
"I miss Will so much. He's got such a maturity and professionalism about him, and he's such a big character. We had a fantastic banter and shared so many laughs together over the years. I don't want to give too much away, but I'm hopeful that he may return later on in the series, even if it's only briefly."
Will there be any romance for Tom in this series?
"No, I think they've given up on Tom's love life for the moment! I think they've accepted that Tom's relationships are always going to end in tears!"
When you look back on your time on Waterloo Road, does any particular story or episode stand out as your favourite?
"The episode in Blackpool when Sambuca was dying just broke my heart. It was shot brilliantly, the scenes were beautiful, and we were fortunate that the weather was so great. There was such a lot of love for the character of Sambuca, too. I know it's a cliché, but it really was just an emotional rollercoaster."
After so long at Waterloo Road, are you planning to stick with the show until the very end?
"I'm going to keep an open mind. We're midway through filming series eight, and thus far I'm having a great time. I approach each series as almost like a new job, though, so if people are still interested in the character and I am too, maybe there's a future for him.
"But I also see myself doing other things in the future. It's just whether that's in the immediate future, or the not so immediate future!"
We asked for reader questions, and a couple of people wanted to know if you'll ever join Twitter!
"Bizarrely, people have tried impersonating me on Twitter and I just think, 'Please - get a life and don't impersonate me!' I'll sound about 138 years old, but maybe I should invest in having a look at how Twitter works, as I don't understand it!
"No disrespect to people that use Twitter, but I don't think I've got the time to comment on what's going on - I'd rather just get on with it!"
When you first joined Waterloo Road, did you ever imagine that it would make it to series eight?
"Not at all. It's very interesting, because it's a very different programme to the one that we started. There are elements that are the same, but back then it was a little bit darker, I suppose. It was a little bit grittier, not quite as glossy, and I guess that means that it wouldn't appeal as much across the generations.
"It's interesting that it's grown into a feel-good family drama. I think that's very important, because there are very few things that the family can sit down and watch. For example, I think The Accused is the best thing on television, but that's not going to appeal to all of the family. So Waterloo Road does what it does very well, and long may it continue!"
> Read the latest 'Waterloo Road' spoilers and news
Waterloo Road continues on Thursday (August 30) at 8pm on BBC One.