DISCLAIMER: I don't own Harry Potter, etc., etc.
The time had been arranged. The entire wizarding world knew it. A remote, empty region of wilderness had been chosen for the setting. There were no muggles for a hundred miles in every direction. Both participants knew where to go, and when. Everything had been prepared for.
Harry Apparated into the deserted field at exactly noon. The bright sun was directly overhead, making the shadow-less scene seem ethereal and bizarre. This place was so silent it was frightening. The air was amazingly clear, allowing him to see for miles in all directions; of course, there was nothing to see. Sand, dirt, and small, struggling plants continued unendingly everywhere he looked. There was no sign of his opponent.
Then, with a slight swishing sound, Voldemort appeared directly in front of Harry. He was robed in monotone black, from head to foot. The only his deathly white hands and ghostly face were visible under the yards of dark cloth that he was wearing. His cruel, red eyes met Harry's, and his thin lips pulled into an evil smile. "So. Here we are, Potter," his high, cold voice rang out. He was some twenty meters from where Harry was standing, but his voice carried clearly across the distance, chilling the boy's soul.
"Let's do this, Voldemort," Harry snapped loudly, making sure he sounded confident. Apparently he failed.
Voldemort's shrill laughs echoed all around, piercing the oppressive silence that hung like a thick fog around the place. Whoever had selected this showdown site had chosen well.
Harry had already decided to attack early and decisively; this was his time. He pointed his wand at the ground in front of the black figure and uttered the Reductor curse sharply, hoping to catch Voldemort off his guard. The ground in front of him exploded in a shower of sand, blasting the Dark Lord with debris. Voldemort instinctively brought his hands up to protect his face. Harry took this moment to strike; he summoned all of his will and all of his power, all seven years of his magical experiences, and forced them into two words. He pointed his wand and shouted, "Avada Kedavra!"
The red beam of magic light shot out like a laser, but flew harmlessly past Voldemort, who had quickly dodged, and, before Harry could recover, shrieked "Crucio!"
Pain ripped through Potter's body, burning his skin and seeming to shred his insides apart. The curse was hellishly terrible, but not debilitating. Harry endured the insane agony and slowly raised his wand, stuttering out the word "Stupefy."
The curse hit Voldemort right in the stomach, as he had not been expecting it. He doubled over, the wind knocked out of him, breaking the Cruciatus curse on Harry, who leapt to his feet and cried "Sagittarius Ignum!" From his wand burst a dozen fiery arrows, rushing toward the crouched form of the Dark Lord.
"Saltus," muttered Voldemort, and he flew into the air, jumping high above the spot where he had just been as the arrows all dove into the sand. He landed several meters away, on his feet, and with a response curse ready. "Incendio," he screamed, sending a massive spray of white-hot flames spewing at Harry, who conjured up a large shield to protect himself. The flaming barrage ended, and Harry dropped the blackened metal to the group, gasping for air. Voldemort smiled again.
"Tired yet, Potter?" And without a pause, he hollered out, "Persolvere!"
The ground around Harry instantly transformed into a thick liquid, dragging him down to his chest, and pulling him quickly lower. "Funis," yelled Harry, and a thick stream of rope shot from his wand, latching on to a large rock nearby the newly formed pool. Just as Harry would have been dragged under, he hoisted himself out of the mud, onto solid ground.
Voldemort howled with thin laughter as he launched another awful spell at Harry. "Manus rapere," he cried, and a giant, skeletal hand, pale and ghostly, appeared out of the air and seized Harry's body, and began to squeeze. The fingernails were long and sharpened, and they began to cut into his skin as the vice-like grip tightened, restricting air to his gasping lungs. With a final breath, Harry managed to puff out the word "Gladius." Instantly a long sword sprung from the tip of his wand, skewering the deathly hand and breaking its hold. Harry swung and chopped off two fingers, then pinned the hand to the ground, burying the sword deep in the phantom-like flesh. But at the moment that Harry glanced up to meet his foe again, Voldemort struck again with double force.
"Serpensortia," Voldemort shouted, and two huge snake were thrown through the air and attacked Harry, wrapping around his legs and arms, pinning his wand hand behind his back and tugging violently, making Harry wince in pain. But the snakes had accidentally aimed Harry's holly wand straight at a large plant creeping along the dusty ground.
"Anima!" gasped Harry. A flash of green light sparkled around the plant, and then suddenly the long tendrils began clamoring up Harry's leg, growing around the two snakes tangled around Harry. The plants wrapped around the reptilian bodies and choked them, pulling them off and then continuing to grow, engulfing both animals in a matter of seconds.
Voldemort had ceased laughing. In fact, his wicked grin had vanished as well. He rolled up his billowing sleeves and held his wand in attack position. "Time to die, Harry Potter."