For just minutes before the vintage train reached Swansea station, one member of the onboard staff received an urgent text telling her she had tested positive for Covid.
So rather than risk the health of passengers who were waiting there to join a £289 slap-up seven-course Christmas lunch, boss David Pitts reluctantly took the decision to cancel the trip.
And the luxury 1930s-style Pullman train, once part of the iconic Orient Express group, ran through Wales without stopping on Wednesday before returning to its base in Carnforth.
Mr Pitts said: “We are terribly sorry to have disappointed passengers at such late notice and left them standing at the station.
“Legally, as all our staff have been double vaccinated, we could have continued and let people travel after ensuring that the infected steward was isolated for the rest of the trip.
“However, passengers’ safety is always paramount so we reluctantly decided to cancel the trip at the very last minute.
“Everybody is rightly very concerned about Covid and so we did not want to take any chances with passengers’ health. However we have managed to rearrange the trip for later in the month.”
The infected steward had recently returned from a holiday in Portugal and had taken a PCR test. She had not shown any symptoms prior to receiving a text saying that the test had proved positive.
For more details of the Northern Belle see www.northernbelle.co.uk or phone 01270 899681.