What began as a childhood dream is now an epic: Louis Palmer's 18-month round-the-world adventure with his self-made "solar taxi". With the power of the sun alone, full of surprises and interrupted by seemingly insurmountable problems, the Swiss teacher goes beyond borders the of precedented mobility. On his way he meets princes, movie stars, politicians and scientists. But the most important encounters are those with the ordinary people of different countries, who he wants to show that a car with zero emissions is not a dream, but an alternative for the future. This film is proof.