For an ethnologist studying the business world the privileged method of immersion is to occupy a function in a company. But how to carry out one’s research work when the company is confronted with a social conflict ? The authorin starts from her ethnographic experience in a common transport company of Marseille in 1995 to show that « neutrality » (with regard to the striking actors) requires commitment, that is declaring herself on strike. But this « neutrality » is instrumentalized at once owing to the informants’ incomprehension of the ethnologist’s position. This situation at its peak becomes unbearable but is nonetheless heuristic.