(upbeat music) - Having Tristan back is absolutely brilliant.

- Always good to have everyone back together again.

I gave him a rather long hug.

I think he was a bit surprised.

- The show has missed Tristan.

We, as a company, have missed Callum.

Now he's back, it's been an absolute treat.

- I don't believe it.

- This isn't a mirage, Helen.

It really is me, older, wiser, more handsome than ever.

It might not be immediately noticeable, but I have actually grown a mustache for this series.

What's all this I hear about Jimmy stealing my thunder.

- What's all this growing on your top lip?

(both laughing) - There was nothing in the script about Tristan having a mustache, and we basically have decided to add in lines about the mustache.

- Siegfried's deeply pleased and relieved to see him alive, and of course, as soon as that relief falls away, he's immediately annoying again.

- What, miss you announce the devil?

Not a chance.

- Sacred occasion, Tristan.

- That doesn't mean we can't have a bit of fun.

- Anyone who has a deeply annoying sibling knows the feeling, he can get under my skin like nobody on earth.

A first class education, and this is what you come out with it.

It beggars belief, it really does.

- [Tristan] Well, I'm a student of life, not the classroom.

- It's nice to see those two getting on so well.

- Tristan is really enjoying being back.

He sort of settles into his own ways back in Skeldale quite quickly.

- It's great fun for Helen to have Tristan back.

- Uncle Tristan, happy to be of service.

- There's eye rolls across the table.

There's those little looks between Helen and Tris and me having Callum back, Rachel having Callum back is lovely because we share a love, some might say obsession, with dogs, and he'll text me sometimes with a picture of Ralph and I'll reply with a picture of Rosie and that kind of thing so I'm thrilled to have that back.

- It's fabulous having Callum back.

I've missed his laugh and also his joy in the lunch order.

We get a choice of lunch every day and he's always relishes the choice, and he always makes me excited about lunch.

But just having his laughter around and his presence, he's brilliant.

- Day-to-day, we just have a lot of fun, everyone on set.

We always have a lot of fun together anyways, and adding Cal into the mix is just brilliant.

- One of the funniest moments is watching Callum and Nick riff off each other and it gets incrementally louder.

So yeah, that, the green room's not as quiet, but we're happy to have them both back together.

- It's been really, really nice returning to the show.

Coming back after lunch on the first day, quite literally felt like I'd never been away for a minute.

Just feels like coming back to a second sort of family, really a bunch of people that you've known for five years.

It's really, really lovely.

(upbeat music continues)