This historical costume drama plays in the Dutch Indies (present Indonesia). The province of Acej, a peninsula of the densely forested giant island of Sumatra, is fomenting with Muslim separatist unrest (it did so again very recently) which is serious enough to cause colonial garrison troops to be attacked, but hard to put down as the inscrutable natives, especially the elite, doesn't play it overtly; although the lower ranks are filled by natives, most of the European cadres lack even enough mastery of the language to feel the pols of their own troops. Yet as a mighty consortium in The Hague decides to act on geological probability of oil reserves right there, it uses its influence with the higher level of the colonial government to order a military convoy to bring the ambitious young geological explorer Frederik Moree immediately to the most promising lake, in the middle of rebel-infested territory