(I own only plot.)
Just as Jasper was about to use the knife that killed his secret love, someone whispered "Don't do it. You'll only give her the satisfaction. Don't let her have us both." He knew the voice and loved it. He smiled warmly at the sound. The voice spoke again, as clear as a bell. "No fear, sweetheart, the only one that can hear me is you. I'll tell you this, you're the only one I want to talk to. And if you don't mind it, I'd like to stay with you. Right here, at your side."
"I don't mind. Actually, I'd be happy to have you there with me." Jasper told the voice, then a light chuckle and a figure formed. A shape crouched down next to him, all white light. It took on a more human form, some new transformation, it was a person. Jasper chuckled. "Well, definitely a more dramatic entrance than a door." He smiled at the figure next to him.
"Hmm, I know. I bet old Vera would have a heart attack if I did this-" She made herself look terrifying "-in her attic bedroom at night. That would terrify the poo out of her." Trudy smiled at the idea. Jasper laughed at the mental image he got. He smiled at the new version of Trudy. She beamed right back and let her new form snuggle close to him without going through. She made herself more solid, so that he could hold her. He tried it out, squishing her gently.
"What I wouldn't have done to protect you from her and marry you. I'd do everything I possibly could to have saved your life." Jasper whispered and the spirit woman sighed. She lifted his chin with a surprisingly warm hand and looked into his eyes. He started to get lost in the deep brown of the ghost's eyes. She softly smiled, but she lifted herself onto his lap and held his eyes with her own again.
"You know that I'd have died anyway, look." She tipped her head back a little and he saw a split running through almost to bone in her throat. Then she showed him a split open wound in her ribs. As he looked at her with a mixture of sympathy and horror, she showed him her wrists. Deep cuts. She noticed that he was scared and felt ill, then she sobbed and hugged him. "I'm so sorry, I must have scared you with that! I know I'm a mess, I do. But I honestly shouldn't have scared you like that."
Jasper hugged the still-solid and sobbing spirit and whispered "No, don't be unhappy. Please. You haven't scared me, trust me. You told me about what she did to you. She deserves to be burned fifty times over until she's fully incinerated. You're too precious to have been treated so brutally. I love you, Trudy. Always have. You're my world."
The Trudy spirit sobbed "I love you, too. You're my universe. I want to be human again, so that you and I could be together properly, no being stolen by the lights until we're old and practically living spores in our chairs." She sobbed some more, ethereally.
"You haven't got the faintest idea how much I wish the exact same thing." He told her. "But no matter what, you're mine. I swear to you, I'll love you to the end of time. You are my beautiful, cuddly fuzz ball." Jasper whispered to her, holding her.
Little did he know that the spirit's capabilities were growing and soon she would be able to do absolutely anything she liked. Even fix the body she came from and return from the dead.