'Jason, MIND THAT ROCK!'

'Rock? Where?'

'Underneath us!'

'You were supposed to be keeping a look-out!'

'Oh, well, blame me!'

'Stop arguing, you two! Keep calm. I am sure –'

'Why is there water coming into the galley?'

'We're sinking!'

'We're not sinking! Everybody calm down!'

'There's water in the galley!'

'The boat's going over to one side!'

'Hold on to me, Ariadne –'

'Icarus, grab my hand!'

'We're turning over!'

'We're sinking!'

'I am sure there is a way of righting –'

'Don't tell me – triangles?'

'It's too late! We're going over!'

'Arrrrrrrrgh!'

'Help me, Pythagoras!'

'Grab my hand!'

'I'm going under!'

'Jason!'

'Icarus!'

'The boat's going over! Jump!'

'I can't – I'm slipping –'

And in a single, sudden movement, the Argo flipped right over, landing on its crew and trapping them in the heaving sea.

All fell silent.

Jason opened his eyes, and immediately felt stinging saltwater rush into them, blinding him, disorientating him. His lungs were burning; it took him more than a moment to register that he was completely underwater and unable to breathe. Quickly he thrashed out with his arms and legs, trying to reach the surface, not even knowing how deep he was – and then he saw it, the light of the Sun, his salvation.

In one smooth movement he propelled himself upwards and broke the surface; a shower of droplets fountained around him, glistening in the bright sunshine. He trod water for a few seconds, catching his breath, trying to take stock of his situation.

Where were the others? Surely they hadn't – No! they couldn't have drowned –

As if in response to this desperate thought, another head broke the surface, shaking vigorously, showering Jason with water. It was Hercules. He stared at Jason for more than a few moments before saying, 'You're still alive!'

'Yes, but what about the others?'

Jason peered then into the translucent water, and suddenly distinguished a flash of blue cloth. 'Pythagoras!'

Without a second thought he dived under, and returned to the surface with an unconscious, but very much alive, Pythagoras. The young man was heavy in his arms: his clothes billowed out and threatened to drag him back under.

'And Ariadne? Icarus?'

Just then a shock of brown hair emerged from the waves, followed by the dishevelled face of Icarus, who had the Queen in his arms. She too was unconscious.

'I can't... hold on to her... much longer,' Icarus gasped, spitting out a mouthful of seawater, looking close to fainting himself. 'Where's the ship gone?'

And Jason glanced around him, wide-eyed, the question occurring to him as well. 'I don't know...'

'Is there anything we can hold on to?' Hercules thrashed at the waves, trying to keep himself afloat. 'Otherwise we'll all drown!'

'Yes, thank you, Hercules,' muttered Icarus. Then, suddenly, 'And what in heaven's name is that?'

Jason and Hercules swung round, following the young man's gaze. Hercules gave a cry of astonishment; Jason blinked, hardly daring to believe his eyes.

Approaching them was a medium-sized boat, but not the sort of boat that any of them had been expecting. This one was sail-less and bright yellow, and moving at a fair speed. Jason tried to cry out, but the cry was lost in his throat, through emotion more than anything else.

'Mac...' he murmured.

'What is that?' asked Hercules.

'Some kind of sea-monster?' asked Icarus.

'It can't be...'

'Can't be what?' asked Hercules.

'It's the Scapha,' said Jason. 'It's Mac's ship... We've... No, I must be dreaming...'

'What are you blithering about?'

But Jason didn't have time to reply, as the craft was gaining on them. Holding tightly to Pythagoras with one hand, he waved wildly with the other, and began to shout – nothing in particular, just the name Mac and an ululating cry that seemed to carry far out across the ocean.

And then the ship was on them, and someone overboard had tossed out first the anchor, and then a couple of orange life-rings. One landed near to Jason, and he grasped it as best he could with his slippery hands; another splashed near to Hercules and Icarus, who stared at it.

'Hold on to it!' yelled Jason.

'But what is it?' breathed Icarus, whose gaze flicked from the ring to the boat and back again.

'It's safety,' cried Jason, grinning suddenly. 'Just hold on to it.'

And Hercules and Icarus both grabbed hold of the ring, too tired to object or even to ponder the strange happenings around them.

Jason looked up at the ship then, and saw a face he knew poking over the railings – the ragged beard, the twinkling eyes, it could only be – Mac.

He gave a cry that was choked with emotion, and sighed with relief as he waited to be rescued.

Pythagoras came to first, his eyes scrunching as he blinked the salt from them; then he coughed, spluttering and choking, his head coming away from the berth as he hunched over coughing; then his head fell back onto the pillow and his eyes opened fully.

Icarus and Jason both ran to his side, kneeling by him. Icarus's hand went automatically to Pythagoras's and he squeezed it; a ghost of a smile appeared on the mathematician's face.

'Where am I?' he murmured.

'You're safe,' replied Jason.

Pythagoras's eyes narrowed then, and he stared at the low ceiling. Then his hands fluttered to the cloth that swathed him. His own clothes were hanging from the ceiling, drying; he was wrapped in a thick blanket. 'The last thing I remember was the Argo sinking...'

They were all distracted then by a cough from the opposite berth. Ariadne had woken up and was being attended to by Hercules, who gave her another blanket as she began to shiver. 'What is this place?' she asked at last, her voice weak.

Here all eyes went to Jason, who was, it seemed, the only person who knew remotely what was going on.

'The Scapha,' replied Jason, hesitantly. 'It's a ship... but a ship... from my time. The future, I mean. I think we've travelled in time.'

'What?!' Pythagoras, usually calm and composed, sat up in uncharacteristic astonishment. 'But surely that is impossible...'

'Well, not entirely, as I must have travelled in time to get to Atlantis,' Jason said, reasonably. 'When we went under... somehow we must have found a way back. Back to my own time.'

His four companions stared at him, shocked and speechless.

'Well, at least we didn't drown,' said Jason lamely. Then, changing the subject: 'You must be hungry. I'll see if Mac's got anything to eat.'

They were still watching him as he left the room. At great length Hercules spoke.

'That's not possible,' he said gruffly. 'We can't be in the future. That's ridiculous.'

'It is not entirely impossible,' Pythagoras chipped in.

'I suppose there's an equation for it,' snorted Hercules.

Pythagoras fell silent. Admittedly he didn't like being out of his depth when it came to science; he was just as confused as the others.

Just then Jason returned, carrying a brightly-coloured packet. 'They could spare these,' he said, waving them vaguely, forgetting rather that the others probably wouldn't recognise that particular brand of biscuits, or indeed any brand. He opened the packet and handed them round; the others took them a little cautiously.

'Mac's making some tea,' Jason said then, finding the silence awkward. He knew how strange it must be for his friends: he could remember how he had felt on finding himself in Atlantis. But they would have so much to learn, so many new things to find out about!

Hercules nibbled at the biscuit, and raised one eyebrow. 'Not bad, actually. But what is it?'

Jason could only show him the packet once again. The silence was broken by the entrance of Mac, who was carrying a plate with five mugs on it. 'Here you go. Milk – sugar –' he handed Jason a jug and a pot, 'and tea for all of you.' He handed round the mugs, noticing how bewildered everyone looked and feeling a little disturbed. 'Anyway, Jason – you were going to tell me who all these people are, and where they all came from.'

Jason closed his eyes momentarily. 'Yes, I was,' he said, slightly reluctantly. 'Very well then. But I should warn you – it's a long story...' He paused. 'And you're probably not going to believe it.'