The new volume takes place in the African metropolis of Marrakech, where the kids spend their autumn vacation. In the winding alleys, they soon meet a boy named Abdel and a girl named Saida. When a deserted baby is found on the street nearby, they try to track down its mother. However, they stumble upon a dark secret – and someone is determined to prevent it from being uncovered at all costs. A dangerous case for the Kaminski kids...