Just a guess, but the Orient Express?
https://www.seat61.com/OrientExpress.htm
1980s: In the 80s, a faster and better-timed train ran between Paris & Vienna during the summer months ('the Paris-Vienna rapide'), in addition to the Orient Express. The Orient Express's Paris-Vienna seat cars, couchette cars & sleeping-car were transferred to this train when it ran. The Paris-Vienna rapide left Paris earlier than the Orient Express, around 17:15 whereas the Orient Express left the Gare de l'Est at 23:15, and it arrived in Vienna the next morning, as opposed to mid-afternoon. On the days of the week when the Paris-Vienna sleeping-car was extended to Bucharest, it would have a long layover at Vienna waiting to be attached to the Orient Express for its onward journey to Romania.