Pete Jackson is halfway through a very good answer when the sentence he’s trying to keep rolling finally collapses. “I hope this isn’t going in verbatim,” he says, giggling. “It’ll be the longest, most nonsensical quote ever.”

He’s had a bit of a busy week, bless him. His series Somewhere Boy, one of the best things you’re likely to see on TV this year, has been plastered with five-star reviews, and has just reached its conclusion on Channel 4.

We got in touch to chat about the big emotional crescendo which saw Danny, the boy who was kept hidden away in fear of fictitious monsters for the first 18 years of his life by his dad, returning to his childhood home again. Spoilers, obviously, abound.

What are the key moments of the finale for you?

It's Danny being able to go back and realise that the world he essentially grew up in doesn't exist – it never existed. Which is sort of an allegory for how we grow up, and how we would long, when faced with the complexities of the real world, to dive back into those fictions that were created for us as children, those comforting little worlds. Danny’s drawn back to see if it really kind of existed or not – of course, it doesn't. And so we return to it through flashback, because the last night is the night that it all really falls apart. His dad reveals who he really is. Danny understands everything about that house, it's just that he's not prepared to accept it fully until he's experienced everything that he's experienced throughout the series. So when he goes back, he's almost allowing himself to live through it for the first time.

somewhere boy ending
Channel 4

Did you have any alternative endings mapped out?

No, not really. It was always going to be like this. The theme running throughout is whether the monsters are real and if they are real, then who is the real monster. Danny grows up believing that monsters are outside, then when he's released and he's told that his dad's a liar, he's offered the opportunity to reframe his dad as telling the truth because he's given a monster to focus on. And across the series as he realises that monster, that one man that killed his mum, is anything but – it's just another broken down human being that made a terrible mistake – his focus shifts very slowly back towards his dad as potentially being the real monster. If the world outside actually is a place of humanity and warmth, then his dad did a monstrous thing in keeping him away from it. However, it isn't as cut and dried as ‘well, his dad's the monster’, because his dad still did provide a place of love for him and, and in the end did set him free in the strangest way. Realising that he trained Danny to kill the monsters, he realised that Danny had to kill [him] so he could move on with his life. [It was a] terribly misguided and dreadful, dreadful thing to do, but he did set him free. So in the end, Steve is the one that did something most monstrous, but he's not entirely a monster either. He's himself a broken down man consumed with grief that did one terrible thing, and then it spiralled out of control entirely.

Why did you decide Danny had to kill his dad?

Danny's put an end to it on his own terms. If he's grown up believing that the monsters have to be slayed, and then his dad’s finally accepted himself as the monster, he allows Danny the opportunity to kill the monster and then move on with his life. Because if Steve was to kill himself, then Danny wouldn't be the one taking control. He’d just be dragged from one place to another. In the end, it's Danny that is allowed to take control of the situation. It's complex, obviously, because the moment Steve accepts that he's the monster is possibly the least monstrous thing he does. Which doesn't let him off the hook either, but does humanise him a little more, perhaps. I always wanted for these characters and their motivations to be messy and complex – no-one's ever right and no-one's ever entirely wrong – and for them all to be the mass of messy, human contradictions that we all are. And so I always wanted to stay away from being able to point at one any one character and say, ‘well, they're the bad guy’.

Why end the series on Aaron and Danny?

Since he was dragged out Danny’s experienced friendship, he’s experienced the love of family, he’s experienced romance. And although it's all been complicated, kind of a mess, and awful as well as brilliant. He doesn't want to cocoon himself away anymore. He sees [the house] for what it is, he sees it so differently than he did weeks before when he was dragged out and is able to kind of look again at what his dad did, who his dad was, how it all ended. And as a result he knows what he wants: he wants the real world, as complex and as awful as it is. It's not safe, and it's not simple, and it's not comforting, but it's real. Aaron is one of those very real things. Danny’s been given a complicated, difficult but genuine and real friendship.

Somewhere Boy is available on All 4 now.