Professor Albus Dumbledore stood solemnly watching the battle unfold from within the Room of Requirement. He could see that the defenders of the castle had done far better than he could have ever hoped. Everywhere that Voldemort's servants had clashed with the teachers, Order Members and DA, the Death Eaters had come off worse and were now in retreat. In addition, the Death Eaters and giants were involved in fierce battles in the Forbidden Forest and the lake. In the forest Hagrid, with the assistance of Firenze, had managed to persuade more of its denizens to come to their aid than anybody could have hoped. Aragog and his children had cheerfully joined in, both to aid Hagrid and for the chance to feed upon the Death Eaters, something Dumbledore was uncomfortable with but accepted as necessary. Firenze had managed to persuade a small number of his fellow centaurs to join him in resisting Voldemort, and the centaurs proved very effective in making hit and run raids upon the Death Eaters flanks, withdrawing before they could be targeted with many spells. Grawp had also proved his worth, leading the few giants that had decided to fight against Voldemort into a vicious battle with the forces of Gurg Golgomath.
Meanwhile, a few Death Eaters had attempted to outflank the defenders of Hogwarts by crossing the lake in the small boats the first year students used every year. Just as the boats reached the centre of the lake, the giant squid sunk them, leaving the Death Eaters stranded. Some giants were sent to aid them, but the instant they set foot into the lake they were attacked by merpeople. The lake was now the scene of fierce combat, as the giants and Death Eaters attempted to either fight their way across the lake to the castle or to safety amongst their fellows.
Dumbledore knew, however, that this would not last. Although the defenders had performed far beyond his wildest expectations, they had suffered losses. While there were many more wounded or captured Death Eaters than there were defenders, several of the defenders had died in the desperate defence of the castle grounds. Also, the Death Eaters were now consolidating into larger groups. Sooner or later, they would overwhelm the defenders, by sheer numbers if nothing else, at which point they would be able to enter the castle. This didn't even take into account the Death Eaters Dumbledore could already see making their way through the Hogsmeade secret passages into the school. "I fear," Dumbledore tiredly told his phoenix, "that I may have made a mistake in permitting the Death Eaters access through the secret passages. The students will soon have to fend for themselves. However, we must do the best we can with the situation." Dumbledore swiftly conjured three rolls of parchment and a quill which he used to write three letters. "Would you please take these letters?" Dumbledore asked Fawkes. After seeing the magical bird incline his head indicating that he would, Dumbledore continued "Take the first letter to Hermione Granger then deliver the second to Charlie Weasley and the last to Remus Lupin." As soon as the phoenix took the letters, he vanished leaving Dumbledore alone in the room. "Now," the old professor said to himself "all we can do is wait and see what Tom has planned for us." He tiredly turned his attention back to the models of the school. They now showed the defenders of the castle withdrawing to its safety, though every one of their faces clearly showed the knowledge that the school itself would soon be under siege. Dumbledore silently watched as the Death Eaters renewed the battle, trying to determine where he could most effectively intervene.