It has never been done in Champions League history, but when Barcelona welcome Bayern Munich to Camp Nou on Wednesday night they will have to overcome a 4-0 deficit to stay in the competition.
Competing in their sixth successive semifinal, the Catalans were taken apart in Germany by a Bayern side who showed them no mercy.
Goals from Thomas Muller (2), Mario Gomez and Arjen Robben sparked a week of talk debating whether this will be remembered as the time Barca passed the torch of dominance to the recently crowned Bundesliga champions.
On Monday morning, Catalan newspapers Sport and Mundo Deportivo led with headlines which focused on "The Comeback."
It all has a similar feel to the build up for the second leg against AC Milan in the last 16, except this time they're 4-0 down and it's Bayern—not the Italians—who are rolling into town.
Barcelona: Victor Valdes; Dani Alves, Gerard Pique, Marc Bartra, Adriano; Sergio Busquets, Xavi Hernandez, Andres Iniesta; Pedro Rodriguez, David Villa, Lionel Messi.
Bayern Munich: Manuel Neuer; Phillip Lahm, Dante, Jerome Boateng, David Alaba; Bastian Schweinsteiger, Luiz Gustavo; Arjen Robben, Thomas Muller, Franck Ribery; Mario Mandzukic