Sirius, fed up with his best friends self-hating regime and his cousins broken heart, decides to fix them up once and for all. He realizes that the only way Remus will give up hating himself and get with Tonks is if he's told to do so by himself. So that is exactly where Sirius has sent them. To 1977.

After James and Lily died, what much was there to do except wait for those that they love. Here they are joined by the people in their family who lost their lives.