The fans of the Basque team had clubbed together to charter a jet specially for the match to ensure that they could not be undone by airline schedules, industrial action or any other unforeseen cancellation.
There was only one tiny flaw in their plan: instead of chartered a flight to the Romanian capital of Bucharest, they chartered one to Budapest, in neighbouring Hungary.
They only discovered their mistake when they landed in the wrong country, but the plucky fans immediately set about trying to make the 400-mile dash to the Arena Nationala in Bucharest by car, train or bus... though on realising that their return flight was booked for just a few hours after the final whistle, they reluctantly had to accept that they would have to watch on TV.
Still, maybe they were better off not making it after all: Bilbao were well-beaten 3-0 by Atletico Madrid on the night.
And they can further console themselves with the knowledge that their mistake is a common one: even the official UEFA stadium announcer at the match opened proceedings by booming out a cheery "Good evening, Budapest!" over the PA system before the match kicked off.