Have you ever been stuck in a cramped, smelly toilet with your grandad? I do not recommend it, even in extraordinary circumstances such as these. Unfortunately, there was no other place at the George Theatre where Frankie and his grandad could activate the Sonic Suitcase without the danger of being seen.

Frankie swung the suitcase onto the cistern and Grandad immediately started typing in the co-ordinates. The little screen blinked and a message appeared. Activate travel sequence?

‘OK, it’s ready,’ said Frankie, excitedly. ‘Let’s go, Grandad.’

But Grandad had a strange expression on his face. ‘I think I might stay here,’ he mumbled, to Frankie’s horror.

‘What? Why? We need to get back!’ insisted Frankie.

Someone began pounding on the toilet door. ‘Open up in there! I know it was you!’ the Agitated Freido yelled. ‘You could’ve killed me – in my own Water Tank of Death!’

‘I like it here in the past,’ Grandad said, ignoring the commotion. ‘If I stay, I’ll be able to see Mavis every day, and I can live among my memories.’

‘But you don’t belong here, Grandad. You need to come now!’ pleaded Frankie, knowing it wouldn’t take long for the battery’s charge to slip below seventeen per cent again.

‘But I’m scared,’ whispered Grandad.

‘Well, that makes two of us,’ replied Frankie with a nervous smile.

‘What happens if things have changed at home?’ asked a suddenly frail-looking Alfie Fish.

‘Well, to be honest I hope one thing has changed,’ said Frankie.

‘What’s that?’ asked Grandad.

Frankie squirmed, suddenly feeling bashful. ‘I hope we’re friends in the future, like the way we are in the past,’ he said.

KNOCK. KNOCK. BANG. BANG.

The Angry Freido had now turned his hand into a fist and was banging on the door. The toilet’s walls were shuddering.

But Grandad paid no attention. He seemed to be thinking about what Frankie had just said. And then he gave Frankie a nod.

‘There’s only one way to find out,’ Grandad said.

Frankie had not been so relieved since the time his mum told him she’d decided against baking him a Teletubbies-themed cake for his birthday.

BANG. THUMP. THUMP.

‘What are you two scoundrels up to in there?’ The Amazingly Agitated Freido seemed to be attempting to break the door down with his shoulder.

‘Let’s go, Grandad,’ said Frankie, and put one hand on the old man’s shoulder.

Then they both grabbed the handle as Grandad muttered, ‘Good luck everybody. Happy travels!’

Frankie pressed ENTER.

At that exact moment, the toilet door fell off its hinges, and in fell a really, really Angry Freido. ‘Now there is going to be trouble!’ he said, as he picked himself up from the stinky toilet floor.

But as the Astonished Freido looked up, he couldn’t believe his eyes – because the scoundrels had vanished. Disappeared in a way he could only dream of doing.

‘What in the name of …?’ he said, completely exasperated.

Clarissa joined him at the doorway. ‘Maybe if you learnt that trick,’ she said, ‘they would book you in New York.’