The exercise focused on a high-complexity scenario on the L3 line. A situation was recreated where a train is stopped inside a single-track tunnel, about 300 meters from the Passeig de Gràcia station, with no possibility of lateral exit. This forced the teams to evacuate passengers through the front door of the train, making them walk along the tracks to the nearest platform.

About 80 professionals from various bodies participated in the drill, including Bombers de Barcelona, Mossos d'Esquadra, Guàrdia Urbana, Protecció Civil, and the Centre d'Urgències i Emergències Socials de Barcelona (CUESB). To increase realism, the exercise was carried out in total darkness, with only the infrastructure's emergency lighting available.

According to sources from the metro's Protecció Civil, an incident of this nature during rush hour could affect up to 1,000 people on a single train. The main objective of the test was to evaluate operational communication in areas with limited coverage and coordination between different intervention teams in a critical situation.