The U Ray — Edgar P. Jacobs

The nation of Norlandia is in conflict with its powerful rival Austradia. The eminent Professor Marduk is tasked by the High Council of Norlandia with militarising a major scientific discovery: the U Ray. However, doing so will require finding a deposit of Uradium, the ore needed to power the ray. And the only known deposit is in an unexplored volcanic archipelago. An expedition is quickly put together, but in the shadows, the Austradian intelligence services are waiting for the moment to act…