It's the fifth Summer Alberto gets to spend with Luca and Giulia. However, this one is unlike any other. Atom bomb threats are all over the news in Italy. Luca and Alberto are scared that their life on the surface will come to an end . As for Giulia, along with all the other humans she's worried her life will come to an end. But, Alberto's determined to keep his promise to Luca; "Can you promise me you'd spend your last moments with me if it were all to end?"