Even if in the first half of the seventeenth century the Dutch East India Company relieved the Portuguese Estado da Índia of most of its possessions in Asia in a series of hard-fought campaigns, the much-coveted Macao remained an elusive prize. On basis of the memoirs of the Swiss mercenary Elie Ripon, the present paper provides some new insights into the failure of the Dutch invasion of Macao on 24 June 1622. The explosion that ended the attack has traditionally been credited to a ‘lucky’ shot from a Portuguese cannon. However, another account has emerged suggesting that it was caused by a ‘clumsy’ mercenary working for the Dutch.