Warning for major character death and grief.
Ladybug stands on top of the chapel roof, looking out on the hundreds of Parisians who were gathered below her. Occasionally she would see someone point at her, or even wave. She ignored them, they weren't the reason she was here.
—
Pulling Hawkmoth's miraculous from him, Ladybug rushed to Adrien's side. She yelled for her lucky charm, barely taking a moment to look at the rose with a red stem and black petals, before tossing it back into the air and trying to cast her miraculous cure.
It doesn't work. The rose falls back to the ground, and she stares at it in shock. She grabs it and tries again. It's the same result.
"No! No no no! Why isn't it working?" She picks it up again. "Miraculous Ladybug! Miraculous Ladybug! Miraculous Ladybug!" She tries again and again, but there's no swarm of ladybugs that fly out to heal her partner like every time before, just a black petalled rose that falls back to the ground. Marinette starts crying as her transformation times out, her suit disappearing in a flash of light.
"Tikki? Tikki, why isn't it working?" Marinette asks, practically sobbing as she clutches the rose and her partner's unmoving hand.
The small god flies up to their chosen's face. "I'm sorry Marinette, but without the energy from an akuma that created the damage, there's no way to cast the cure."
"No. No, there has to be a way to bring him back! He always comes back! I always bring him back. He can't be gone! He can't be… I can't lose him. Please, Tikki! Tell me how to bring him back!"
The kwami just looks at her sadly. "I'm so sorry, Marinette."
—
When Marinette stops crying, her actions are mechanical. Take the ring. Transform back into Ladybug. Call the police. Carry Adrien's body to the ambulance. Give her statement to the police and explain what happened. Direct the police to Gabriel so they can arrest him.
She ignores Tikki and Plagg's pitying faces. She ignores the worried looks that the officers are giving her. She ignores the paramedics shock when they realize it's Chat Noir that she carried to them. She ignores the blood on the office floor and Gabriel's broken face when she revels that the miraculous cure couldn't bring Adrien back this time.
She ignores the news reporters and civilians gathered outside as she swings away. She ignores Tikki and Plagg as they ask if she's okay when she detransforms and goes looking for cheese and cookies for them. She ignores everything, including her parents sleeping downstairs and her phone on the table, until the sun rises and Alya shows up.
—
Alya heard the news when she checked her phone after waking up.
"Hawkmoth revealed, Gabriel Agreste arrested"
"Chat Noir Killed in final battle against Hawkmoth, revealed to be 18 year old Adrien Agreste"
She immediately calls her friend, trying to find out what happened. Marinette doesn't pick up. She calls again, still no answer. Getting dressed quickly, she hurries out the door to Marinette's house, making her way up the stairs and pushing open the trap door to Marinette's room. She finds her friend sitting on her balcony, staring out over the Paris skyline.
"Marinette?" The girl turned to face her. "What happened?"
"He's dead."
"Adrien?" Alya asks quietly.
Marinette just nods.
Alya pulls her friend into a hug. "What happened?" she asks, and Marinette tells her everything.
—
Ladybug watches as the people of Paris line up to pay their respects. They come by one by one, some saying thank you, some leaving flowers or gifts. Some of them are there with friends or family, some have come alone. She sees Alya and her other classmates come. Most of them are crying. She's not though, where she's standing on top of the church. She feels like all of her tears have dried up.
Slowly, the sun starts to set and fewer and fewer people stop by the grave, until eventually it gets dark and the gates of the cemetery close, leaving them alone.
She jumps down from the roof and walks over to the gravestone, detransforming and kneeling beside it.
"Hi Chaton. I'm sorry I couldn't save you. I tried, I really did, but it didn't work. I failed you and I'm so sorry." Marinette lets the tears she's been holding back fall, and she pulls out a rose with a red stem and black petals out of her jacket pocket. "I want to bring you back, to wish for you to be alive again, but I can't do it, I'm so sorry." She places the flower on the stone and stands up. "I love you, Adrien. I wish I could have told you that while you were still alive."
Twelve hours later, she's packed everything she wants to take with her into the magic extradimensional space in her yo-yo, and transforms with the horse miraculous, telling the kwami to open a portal to somewhere where Ladybug is needed.
She ends up landing on top of a nineteen year old crime lord, who tries to stab her. Good thing her suit is magic.