The Ophiuchi Hotline

Prior to the beginning of the story, humanity has been expelled from Earth by powerful aliens known as "the Invaders", and scattered across eight planets and satellites of the Solar System, the so-called Eight Worlds.

Human expansion to the Eight Worlds has been aided by a broadcast of information from outside the Solar System, named "The Ophiuchi hotline" after the constellation Ophiuchus from which it appears to originate.

Related to this, while technology has been developed to allow people to back-up their memories, this is only permitted for implantation within a cloned body in case of death.

However, the night before her execution, a powerful lunar politician named Tweed offers her the chance to escape her sentence by replacing her with a clone killed in her place.

She is given a null-field suit — a conforming forcefield with an air generator that protects her from the vacuum — and is tasked with researching how to kill creatures that live in Jupiter's atmosphere.

She reveals to Cathay that, when she began her original experiments, she put a clone of herself and a backup of her memories in a secret base in Saturn's rings, to ensure her survival in the event that she was executed.

Tweed then awakens another version of Lilo and sends her with a clone of Vaffa to Pluto to research a new message coming from the Ophiuchi Hotline.

Lilo and Vaffa find a second clone of Cathay, and the three of them are tasked to lease a ship from navigators dedicated to hunt for black holes, and go beyond the orbit of Pluto to analyze the message.

Because of her null-field suit which she can turn on at will, she is worshipped as a god by the surviving humans scratching out a living at a pre-industrial technological level.

Somewhat surprised by this turn of events, the extraterrestrials explain that the silver cube is a singularity that can be used for space propulsion by canceling inertia.