This is less of a story, and more of a set of connected one-shots. Focusing on the reasoning of the Black family and those connected to them during Order of the Phoenix and Deathly Hallows. It is a bit angst-y, but it kind of has to be- it is about understanding when it is time to sacrifice.
This first one is the only one set during Order of the Phoenix.
Sirius had given up any chance to be a hero. He would never leave his house by his own choice, to fight alongside his friends and never return. All those decisions he had placed in Dumbledore's hands, and Dumbledore decided that Sirius should stay home while others went out and did the fighting and dying.
Sirius might complain about Dumbledore, and question his reasoning, but Sirius could never really go against him. Dumbledore led the Order into every battle, and was the greatest hero Sirius had ever known.
Dumbledore would sacrifice anything for the cause, even making those he protected hate him, if that is what he had to do.
And Sirius knew that Dumbledore's order for him to remain in the house was something Dumbledore had to do, to protect him. Sirius could be recognized, and shipped back to Azkaban, or Sirius could die and then Harry would have no Godfather. Sirius understood why Dumbledore made these choices.
But when Sirius found out that Harry and his friends were at the Ministry, and in danger, Sirius understood it was time to defy Dumbledore's orders.