I wrote a second (and much shorter) happy ending version for my friend. This one, however, skips around and overlaps with the movie a lot. It starts from the battle at the end of the movie in the keep. I also tried to connect this legend of Tristan with the legend of him as one of King Arthur's greatest knights. I hope you all like! :)
In a flash, Tristan jumped up through the trap door and charged into the Irish soldiers. An archer shot an arrow that landed deep in Tristan’s thigh. But as if he hardly noticed, Tristan struck down the archer and stabbed the man next to him. Ducking a killing sword stroke, Tristan swung his sword and sliced into another soldier’s side.
Hearing the alarming shouts, Marc peaked over the stone wall. "Tristan?" he said perplexed.
"He’s with them?" the man beside him asked.
Regaining courage, Marc yelled, "No, he’s with us!"
Marc and his men stormed down the stairs towards the Irish soldiers. Tristan, fighting with all his might, turned and was stabbed in the stomach by Wictred. But before the blade went in too deep, Tristan sidestepped and pushed Wictred away. He rushed to the drawbridge wheel where the chain that held it had been broken and shoved his sword into the spokes. With a shudder, the drawbridge stopped lowering.
Wictred jumped to his feet and plunged his sword into Tristan’s chest, pinning him against the giant wheel. But no matter how hard he pushed, the sword didn’t seem to go in any further. Grabbing a hidden dagger in his tunic, Tristan plunged it into Witched heart, killing him.
"Tristan!" Marc yelled as he ran to where he slumped down on the floor.
Tristan pulled the sword away from him. He reached into the neck of his tunic and pulled out the small pendent that hung around his neck. A deep indent ran across it. It was a gift that Isolde had secretly given him. He had hung it around his neck close to his heart, concealing it under his tunic. Though small, it was large enough that it stopped Wictred’s blade from piercing his heart.
"How did you get in here?" Marc asked, perplexed.
"Another secret," Tristan weakly joked.
"Secrets...," Marc repeated.
"Will you always be little men, who cannot see what was and could be again?" Marc asked the Irish armies condescendingly. "There is no middle ground! So slay us! Or slay him," he yelled, pointing at the Irish King.
"Oblige them," King Donnchadh ordered. When no one moved, he yelled, "Oblige them!" When again no one moved, he struck out at the soldier standing closest to him, hitting his shield with a resounding clang.
An arrow buzzed through the air, landing in the Irish king’s back. Shocked and angered, he turned to find the man that shot him in the back. With a shout, he attacked the nearest soldiers.
Marc, Tristan, and the other men rushed down from the drawbridge into the fray. The fighting was in mayhem, few paying attention to who they were slaying. Tristan, however, was slowed by the wounds he had received fighting in the keep. Though he fought well, he was not quick enough to avoid receiving many more injuries. He was tired and near collapse
"Tristan," Marc grabbed Tristan’s arm and dragged him away from the fight.
"I can still fight," Tristan argued.
"Tristan, you have already saved us from slaughter and helped us win this battle. You don’t need to kill yourself!" Marc reasoned.
He dragged Tristan across the bridge to the river. "Go. Find Isolde and leave," he said, turning to go back to the battle.
"Marc," Tristan said. Marc stopped and turned back around. "I’ll miss you."
The two men embraced, and Marc walked away.
Where is Isolde, Tristan suddenly wondered.
Then, Isolde appeared, her bag of herbs and remedies slung over her shoulder, led by one of Marc’s loyal friends.
"Where are we going?" Isolde asked. She leaned on the boats side, enjoying wind and the sea mist that blew over the ship.
The day before they had arrived at a harbor town that sailed ships down the river deep into the heart of Britain. There they bought passage on a ship and were now under way, sailing towards their new future.
"The captain said we’re heading towards Camelot," Tristan answered, standing next to her.
"Who rules Camelot?" she inquired.