Pol Myers, CEO of Sol Enterprises, raised his glass and beamed at the assembled passengers. "To Tabula Rasa, and all who fly in her!"

"Tabula Rasa!" echoed the crowd, faces flushed with excitement and adrenaline.

"The greatest venture in the history of the world..."

Dan tuned out as Myers' speech continued. As chief pilot, Dan had been obliged to attend the ceremony but his thoughts were elsewhere. In a few hours, everyone except the crew allocated to first shift would be packed into cryopods for the long journey ahead. He shivered involuntarily at the thought, glad he wouldn't be joining them. At least, not until five years had passed and the ship was beyond Jupiter.

Tabula Rasa, Earth's very first generation ship. Dan marvelled again at this miracle of modern technology. Complete with seeds, tools, survival kits, everything they would need to establish themselves on a new world; Tabula Rasa was humanity's last hope.

Uncertain as their future might be, everyone knew that staying on Earth was no longer an option. Cities constantly flattened by violent storms, coastal plains flooded by rising seas, so choked with plastic that they were killing fish faster than they could breed... Greenpeace might argue till they were blue in the face that the vast resources used to build Tabula Rasa could have been better used tackling Earth's problems, but everyone with half a brain knew it was too late.

Dan frowned, reliving the last conversation with his sister for the hundredth time.

"How can you live with yourself, Dan? You're taking some of our brightest minds, right when they are needed here on Earth!"

"But it's humanity's only hope. Our chance to survive, on a new world."

"I'm sorry, Dan. I know you've pulled a lot of strings for me but I'm not coming." Then she'd added, "I'm staying with Mum... and the millions you and your friends are leaving behind!" They hadn't spoken again.

Tabula Rasa made it all the way to the Kuiper Belt before the aliens introduced themselves. Dan was on the bridge, when a bright light appeared, hovering above his instrument panel. He flinched away, imagining an explosion of some sort would follow, but instead, words began to flow across his screen.

"Greetings, human. Congratulations on achieving space flight. Unfortunately, you've made a bit of a mess of your home planet, haven't you?"

"Gah? Wha—?" for a highly educated man, Dan found himself struggling for words. Maybe he was hallucinating. It had been a long shift. He blinked and rubbed his eyes, but the words were still there, along with the bright light.

"Who are you?" he managed. The bright light continued to hover, pulsing gently. Then words flowed across the screen again.

"We are The Guardians. I'm afraid you'll have to go home and clean it up before we can allow you to travel outside your solar system."

Then the bright light vanished and the screen reverted to normal. Except... Tabula Rasa was now heading back to Earth.