In the summer of 1999, the Serbian Ministry of Health issued a public health warning about the environmental risks associated with the total solar eclipse to took place on 11 August. The warning contained a list of phantom symptoms unknown to medical profession. Some of these included severe itching, hypertension, cardiac palpitation and frequent urination. Despite the warning’s patent absurdity, the Serbian public widely observed it by seeking indoor and underground shelter from the lunar shadow, participating in what I term a ‘great public disappearing act’. By contrast, the rest of Europe and the Middle East embraced the event as a public spectacle, with millions thronging the streets and observation posts. This paper raises two key questions: Why did the Serbian government issue the odd warning? And why did the Serbian public observe it? In contrast to the conventional readings of the event as a compound effect of a political manipulation and a lack of public scientific education, I argue that the public behavior on the eclipse day was a meaningful response to the social, political and environmental circumstances in the worn-torn Serbia. Using insights from the social amplification of risk framework, I demonstrate that the great disappearing act was a paradigmatic example of herd behavior governed by the media-driven informational cascades. I further argue that the actors involved in the production and reproduction of phantom ecliptic risks – doctors, journalists, government officials, ordinary citizens – jointly enhanced their plausibility in a way that eventually eliminated the possibility of any behavior not mediated by the cascading processes of risk production.