Only one pair was still battling, apparently unaware of the new arrival. Harry saw Sirius duck Bellatrix's jet of red light: he was laughing at her.

'Come on, you can do better than that!' he yelled, his voice echoing around the cavernous room.

The second jet of light hit him squarely on the chest.

The laughter had not quite died from his face, but his eyes widened in shock.

Harry released Neville, though he was unaware of doing so. He was jumping down the steps again, pulling out his wand, as Dumbledore, too, turned towards the dais.

It seemed to take Sirius an age to fall: his body curved in a graceful arc as he sank backwards through the ragged veil hanging from the arch.

Harry saw the look of mingled fear and surprise on his godfather's wasted, once-handsome face as he fell through the ancient doorway and disappeared behind the veil, which fluttered for a moment as though in a high wind, then fell back into place.

Harry heard Bellatrix Lestrange's triumphant scream, but knew it meant nothing — Sirius had only just fallen through the archway, he would reappear from the other side any second . . .

But Sirius did not reappear.

'SIRIUS!' Harry yelled. 'SIRIUS!'

He had reached the floor, his breath coming in searing gasps. Sirius must be just behind the curtain, he, Harry, would pull him back out . . .

But as he reached the ground and sprinted towards the dais, Lupin grabbed Harry around the chest, holding him back.

'There's nothing you can do, Harry — '

'Get him, save him, he's only just gone through!'

' — it's too late, Harry.'

'We can still reach him — ' Harry struggled hard and viciously, but Lupin would not let go . . .

'There's nothing you can do, Harry . . . nothing . . . he's gone.'