"A Short Autumn" Witnessing a series of accidents on the street – a prostitute's dog jumps from a balcony, causing a passer-by to be struck by a taxi and another to have a heart attack – Martín and Mariana separately stop to help.

Martín is diagnosed with a harmless case of discarthrosis and has adopted his ex-girlfriend's dog after she abandoned them both to move to the United States.

Explaining her phobia of elevators, she takes the stairs, to Lucas' dismay; as he waits at their table, she is overcome with anxiety and leaves.

Finding Martín's old office chair on the curb, she brings it home, and deletes all her pictures of her ex-boyfriend from her laptop.

By chance, they connect with each other in an internet chat room, but just as Mariana asks for Martín's phone number, the city is plunged in a blackout.

During the closing credits, a YouTube video is shown of Martín and Mariana – now living happily together – lip-syncing to "Ain't No Mountain High Enough".