Harry Potter and the Dark Lord's Castle
Orders of the Good

Meanwhile back at Hogwarts...
"I knew I should have never left him alone!" Sirius ranted, he had been talking like this for the last hour, ever since they realized that Harry was missing. "I was with him and I should never have left! I should have realized that the Death Eaters would want revenge and that they would extract it out on Harry!"
"Sirius, calm down, it is not your fault, it is mine. I should have posted more security around the castle, I should have asked one of the professors to follow Harry and make sure that he was safe." Dumbledore said
They both knew that their arguing about whose fault it was wasn't helping the situation but neither of them wanted to accept the fact that Harry was in the hands of Lord Voldemort, and their arguing was giving them time before the truth set in.
"Dumbledore! Sirius! What has happened?" Professor McGonagall burst in to Dumbledore's office. "Is it true? Severus told me that Harry..." Her voice cracked and she couldn't go on.
Dumbledore nodded, "It is true Minerva, the Death Eaters were here, they came out of the Forbidden Forest and attacked Harry. They stunned him and took him prisoner." Dumbledore looked old and downcast as he said these words.
"Albus, how will we rescue him, what can we do?" Professor McGonagall looked frightened of the possible answer.
"Unfortunately there is very little that we can do Minerva." Dumbledore looked very tired, his face was very pale and he looked sick. "If we attack, Harry will be dead before we can get by the first guard. We can only hope that Voldemort has some reason to keep Harry alive. If he doesn't, than Harry might already be dead, we need to find a way to lure Voldemort and his guards away from his prison so we can attack and rescue Harry."
"How can we do that? What should we do now?" Minerva asked impatiently
Some of the fire came back in to Dumbledore's eyes as he sat up and answered her question. "First things first, we need to be sure of any allies we have or can get. Minerva I need you to contact Hagrid, ask him if he has had success on his mission and if we can count on support from the giants. Then I need you to talk to Arthur Weasley of the Ministry of Magic, ask him if we have support in the Ministry and who we can count on." Minerva was expecting this so as soon as Dumbledore finished his instructions she stood up and left the office.
"What should I do professor?" Sirius asked, looking after McGonagall
"Sirius, I need you to do a mission that I know will be very hard on you, but you must do it."
"What mission? I'll do anything for Harry." Sirius said anxiously.
"You don't understand Sirius, I need you to nothing, I can't have you trying to rescue Harry, most likely you'll die in the attempt and will be condemning Harry to death. Sirius, I am asking you to wait.