In this book, the humans meet their first aliens, the friendly reptilian Ringulian people.
The humans are terrified, knowing that they.
They are sinister, brutal space pirates, who decide to wage a space war against the Earth people, the Ringulians and Kalesians.
The humans then hear from the Gloshans.
The Kalesians live on the planetoid, rocky world of \'Pluto\'.
The Ringulians live on Jupiter\'s ice moon \'Europa\'.
Next come the Kalesians, willing to share their space technology with the humans.
In this book, the humans meet their first aliens, the friendly reptilian Ringulian people