Asterix and the Great Crossing

Out at sea fishing, Asterix and Obelix are blown off course in a storm. Luckily they land on the shores of a Roman colony - or is it? Teepees, totems, gobbling birds: it's not what they're used to. And what are the Viking explorers in their longship doing? But perhaps 50 BC is a little too early for a voyage of discovery to this strange New World...