A worsening coronavirus outbreak in Taiwan has raised urgent questions about how the virus slipped past Taiwan’s “gold standard” defences, and if the country can quickly return to a zero-Covid life. In 2020, the island state of 24 million people was producing extraordinary numbers: fewer than 1,000 cases, about 90% of them detected in recent arrivals, zero infection leaks from quarantine, a death toll of 12, and 253 days without a single local case. On Friday, the numbers turned when health joker game authorities reported 29 local cases, followed by 180 on Saturday, 206 on Sunday, and 333 on Monday. Most are in the north, with large clusters in Taipei city and New Taipei city, where testing stations have reported 10% positivity rates. About 91% of Taiwan’s total local caseload has come in the past four days. The outbreak began in late April, connected to flight crews from the national carrier, China Airlines, and a Taoyuan airport Novotel, which was hosting both quarantining flight crews and Taiwanese flight enthusiasts who had booked in as part of a domestic tourism promotion. Both the airline and hotel have since been fined. The first cases were reported in two pilots on 20 April. Ten days later, the Central Epidemic Command Centre (CECC) announced an investigation into “the possible risk of transmission” among staff who had quarantined at the Novotel in the previous two weeks. The cases confirmed fears about the government’s decision to steadily relax required quarantine time for flight crews, down to just three days by mid-April. By the time of the investigation many crew members had checked out and some were later found to have visited public venues while infectious. Dr Chiou Shu-ti, former health commissioner of Taipei, said authorities were “playing with fire” by relaxing the requirements while being “complacent” with testing of arrivals. By early May, 18 airline and hotel employees and 11 family members had tested positive, and soon cases emerged in counties without a known link to the airport or hotel. By Monday, there were cases in nine cities or counties, all reportedly the same UK variant of the virus.