This study examines the confrontation between Taiwan and Covid in the period before the virus finally invaded and spread widely on the island in May 2021. While the general approach to Taiwan’s success in keeping the virus out is historical, stating the policy lessons learned from previous anti-pandemic experience, the study focuses on how these coping strategies were able to be made and conducted with little disruption from misinformation and conspiracy theories. Inspired by Sheila Jasanoff’s notion of how science and technology are received through different political and policy systems, and by Bruno Latour’s semiotic reflections on the actor-network theory, the STS take on post-truth politics here is institutional and discursive: instead of focusing on the scientific and the misleading in individual policies, I provide an ethnography of rumour and scientific discourse on Covid, capturing their interactions and net effects in the context of policy discussions. Following closely the daily press conferences held by the Central Epidemic Command Center (CECC), the only official information source for the Covid pandemic, I argue that discursive frames were made upon the limited information given and few confirmed cases found. Through the expert authority and ‘what if?’ scenarios seen at these conferences, Taiwan’s anti-Covid policies came to be presented as a narrative on crises and what the government was doing to get over them, and rumours were either ignored or marginalised. Meanwhile, though disputes and speculations on pandemic control did exist among experts, they only surfaced after the local outbreak, whereupon conspiracy theories flared up, challenging the already exhausted CECC. Together, the excessive information by experts, health professionals, policy analysists and talkshow hosts composes a ‘post-truth normal’ that has started to place Taiwan’s democracy and its trust in expertise on trial.