Gaullish custom requires that a would-be chief must challenge and defeat another to become the leader of two tribes. Vitalstatistix is not perturbed because of Getafix's magic potion. Getafix, however has an accident and forgets how to make it. Then Vitalstatistix is suddenly challenged.
When Getafix becomes an amnesiac lunatic after being struck by Obelix's menhir, Asterix tries to cure him, all while his fellow villagers are being conned by a phony soothsayer Prolix.