While d'Artagnan crossed swords with Gontard, Athos fought against the Duke, though he didn't fight with as much ferocity as he usually did against his opponents, as the musketeer hoped not to have to kill the man, only to keep him from striking out against their fallen brother again. Unfortunately, the Duke wasn't leaving Athos with much choice.
The Duke smiled cockily as he continued to fight against the musketeer dressed in all black, then finally spoke again smugly saying, "I know you want to kill me. Just as I saw it in your eyes back then, I can see that you want to kill me now more than ever, but you're not fighting like I know you can. Why are you holding back? Is it because you know that if you kill me, this traitor you three are protecting will not be the only one to die because of what happens here today?"
Aramis fought against Porthos to sit up straighter within his arms, then called out to their leader weakly, "He's ri… right… Athos. Please…"
"The four of us are in this together," Athos answered Aramis while continuing to stare down their enemy before him in between the clashes of their swords. "This is more than the oath we took back when we became musketeers. We are brothers. We protect each other at all costs, so long as we remain just. And you, Aramis, are one of the best men I know."
"You're my closest friend," Porthos added swiftly. "Now hush."
The Duke grew angry, increasing his ferocity against the musketeer, who realized that this battle had to end now, or Aramis wasn't going to survive much longer, so long as he remained out in the cold. Finally, the youngest musketeer managed to strike down Gontard, firing a musket ball through his heart as the Duke's right hand attempted to thrust his sword into d'Artagnan's chest. Gontard's death was the distraction Athos needed, as the Duke turned his head the moment his advisor fell, allowing Athos to run his blade into the lord's abdomen.
The Duke's death was slow, as he began to choke on his own blood, so Athos pulled out his own pistol and fired a ball directly into the man's heart to end his suffering. When both enemies were dead, Athos and d'Artagnan quickly ran over to their friends as Porthos attempted to lift Aramis from off the ground upon seeing that his consciousness was fading. However, as they did so, another rider coming toward them fast and when the rider came into view, they immediately saw that it was the Duchess.
Upon seeing her husband dead upon the frozen ground, she screamed, "No! You killed him! You weren't supposed to kill him!"
Athos stood quickly as he slowly approached her, despite the pistol she pulled out from beneath her cloak and aimed it directly upon the musketeers who once helped her when her secret was about to be blown, then he spoke calmly saying, "As opposed to what, my Lady? Did you just expect that we would simply believe that the Duke orchestrated the poisoning of your people and that we would go back to Paris with the two of you and your son in tow, counting on your brother showing mercy on him so that he would be exiled and that you and your son would be free, to live once again in Paris where you long to return to?"
"I loved my husband," she replied coldly. "I didn't want to hurt him. I loved him, but I knew that he would never give up his power for me, so I did the only thing I could think of. I hate Savoy! I always have. Louis would have spared his life. We would have been free to live together in Paris, but your friend there had to interfere, getting the rest of you to investigate."
"Our friend did all he could to save as many lives as possible," d'Artagnan responded worryingly as he slowly moved to stand beside Athos, while Porthos remained back with Aramis. "Is what you did worth the lives you destroyed, including that of your husband's, of your son's?"
She quickly aimed her gun in the younger musketeer's direction as she stated, "I didn't destroy my son's life."
Athos continued, "Don't you realize that when he learns his father is dead and that his own mother was responsible for his death… Don't you know that this will crush him?"
"Why did you tell your husband about Aramis?" Porthos asked her angrily. "What did revealing what you overheard Athos and I speaking of do for you? We helped you when your secret was about to be revealed, and this is how you repay us?"
"I had no choice," she answered curtly as she looked down at the wounded man on the ground. "He was trying to stop what I was trying to accomplish. He was trying to ruin what I started, so I had to stop him."
Athos swiftly disarmed her the moment she turned away from him and she cried out until she finally gave up her struggle with the musketeer's arms, then he glared at her as he asked, "What was the poison you used? What poison did your friend that we arrested use on your people?"
She looked up at him with hate in her eyes as she replied coldly, "The angel of death has come. You will never save them or your brother."
"Aman… ita ocre… ata, of course," Aramis suddenly spoke again, barely above a whisper, as he tried to focus on Porthos face. "Belladonna. You need… bella… do…"
"Aramis!" Porthos cried, panic stricken as he gently patted his comrade's cheek as he slowly fell unconscious before being able to finish. "Aramis!"
D'Artagnan rushed over to his friends to help Porthos lift Aramis into his arms, while Athos guided the Duchess back over to her horse, then tied her hands tightly around the saddle's horn so that he could also help his friends as he said quickly, "We need to get him someplace warm and where we can patch him up. We can't go back to Savoy, not after killing the Duke, but we can take him back to the inn where we rested before coming here. We'll take the Duchess with us."
Once the musketeers moved to their horses that were standing nearby, even after their riders had jumped off them to fight their enemies, they carefully lay Aramis within Athos' arms as soon as he had mounted, D'Artagnan asked, "What about the poison? What was Aramis trying to tell us?"
"I believe he was trying to tell us the cure," Athos responded wearily. "Which is why as soon as we get Aramis to safety and as comfortable as we can, two of us must head back into the city to try to gather as much of this, belladonna, as we can to try to save the rest of the people, while the other remains behind to stay with Aramis and the Duchess. Then, we'll be back to give the cure to him too."