After an entirely uneventful summer, the arrival of helicopters full of soldiers, an unusual looking black train and a curious burst of light during a storm, leads twelve year old Arthur to discover that he is suddenly able to talk to his ever so sarcastic cat. The retrieval of a little black box, ends in them being taken to a restricted government facility where they not only discover the existence of a secret global project to build a space ship based on artefacts and plans retrieved from a meteorite, but that Arthur and his cat are the only ones who are able to make it all work. In a drastic turn of events the mission is forced to launch.

Their arrival at their destination in the far reaches of the universe appears to go unnoticed, and euphoria quickly turns to trepidation. Forced to take matters into their own hands, a small party is sent down to the planet''s surface to try to make contact. But no sooner have they landed they learn that their ship has been captured and their crew taken hostage, including Arthur''s father. On the run, they make their first alien contact with the planet’s resistance, where it transpires that they have arrived on the eve of the final battle of a 100 year war against an evil empire. Called upon to join the resistance efforts, they are thrown into the thick of the fighting, on a world where wars are fought with giant robots, strike ships and levitating tanks. With victory secured, a daring mission is devised to rescue the captured crew. Injured, Arthur wakes to find that his father is still missing, and he is more determined than ever to get him back.