In April 2010, Iceland’s glacier-capped volcano Eyjafjallajökull erupted after nearly two centuries of dormancy. Though modest in size compared to historic eruptions, its impact was global. When molten magma met the glacier’s ice, powerful steam-driven explosions hurled a massive ash cloud into the atmosphere. Winds carried the ash over Europe, forcing aviation authorities to ground flights for nearly a week. More than 100,000 flights were canceled, affecting an estimated 10 million passengers and costing airlines $2 billion in losses. Airports became shelters for stranded travelers, and global supply chains faltered. Locally, Iceland faced flooding, ashfall, and damaged farms, though remarkably, no lives were lost. Globally, the event was a wake-up call, showing how even a relatively small eruption could disrupt modern systems of travel and commerce. The Eyjafjallajökull eruption stands as a reminder that disruption can be as devastating as destruction—and that nature can halt even the busiest skies with little more than an invisible cloud of ash.