Marlene McKinnon was quite happy in Paradise. She had Lily, James, Regulus, and her family to keep her company. She even got to stay with them all at Hogwarts for as long as she wanted. Paradise was the same as being back on Earth, but there was a whole world of difference. It was sunny and beautiful all the time. Everyone was happy. The loved ones you thought you'd lost were still there, and you got to speak to them and hug them without thinking you've gone mad.
When somebody entered Paradise, everybody knew. They didn't ask about the new person's death, and instead, kindly greeted and welcomed them. Anyone was welcome in Paradise, that is, unless they've proven themselves to be evil. In Paradise, there was only good. Criminals and Death Eaters were only allowed in Paradise if they proved themselves good before their deaths. If they didn't, they went to another dimension that the citizens of Paradise never liked to mention.
In Paradise, you can go anywhere you please. Marlene stayed at Hogwarts mostly, but every day at the same time, she traveled to King's Cross to watch over her loved ones. At King's Cross, you could hop on a train and view everything that is happening on Earth. Lily and James often did so, and kept an eye on their son, Harry, though Marlene was more interested in watching over an old friend.
Marlene often took the Hogwarts Express to watch over Sirius Black, her past lover. Paradise often lets you walk on Earth, as though you were really there, but nobody can see, feel or hear you. You're nothing but a spirit. Marlene did that a lot. When Sirius was in Azkaban, she would lay with him and sing soft lullabies to him at night. She stayed with him, like she once promised she always would. She remembered it, clear as day, when she told him, "I'll always stay by your side."
When Sirius escaped Azkaban, she followed him. She hated how he had nowhere to go. The Shrieking Shack wound up being his home, and she tried making it warmed with magic, but that never worked. Paradise would never let you interfere with the mortal world. Instead, she just hugged him and held him when she could. She only hoped that her very spirit could offer the least bit of warmth. She had often been told she had a warm heart.
Marlene continued watching over Sirius, guarding and protecting him as though he were her last bit of sanity for the next two years. It wasn't until the day he died that everything changed.
It was a day like any other in Paradise; sunny, warm, happy. Everyone was in a good mood, as it had rained the weekend previous. The sun seemed to lift everyone's spirits. At the same time as usual, Marlene apparated to King's Cross and boarded a train. This time, it didn't take her to Grimmauld Place, where she normally found Sirius. This time, it took her to a dark, mysterious looking room. It seemed that there was a massive duel going on, between the Death Eaters and the Order of the Phoenix. Marlene watched anxiously as Sirius dueled with his cousin Bellatrix. How she hated his cousin... As soon as she heard Sirius bark out a laugh, she knew he'd let his guard down. Marlene threw herself between Sirius and the oncoming curse, but it was no use. It simply passed right through her.
Marlene daren't watch her lover die. She just couldn't bear to see it. She knew she'd still see him at King's Cross, but the thought of losing him, not being able to hold him or keep him warm... It scared her. She quickly apparated to King's Cross, taking a seat on a bench while she waited. He'd fallen through the veil. He should be here any moment. And she waited. He's proven himself to be a good person. He must be still deciding whether he wants to be a Poltergeist, or a ghost, or come up to Paradise. And she waited... Until she heard a crack. She lifted her head, and a wide grin spread across her lips.
"Look at you, old man. It's about damn time you arrived, I've been waiting here sixteen years!" she teased, getting to her feet.
Merlin, just the sight of him was enough to make her heart race. He wasn't old, like he was when he died. He was the same twenty-one-year-old she'd been engaged to before she was killed. The long, shaggy hair; the captivating grey eyes; that bloody smirk that drove her crazy… And the ring. The one she had never seen him take off; the one that matched that which would have been her wedding band. She ran up and threw her arms around him, kissing him with all the passion she could muster, grinning as he lifted her up and swirled her around. Not even Paradise could make her that happy.
Together, they traveled back to Paradise. Lily and James were thrilled to see their old friend, and Mr. and Mrs. McKinnon pleased to meet the rascal who had swept their daughter off her feet. I guess you could say that Marlene and Sirius got their happy ending after all. In Paradise, they finally married, and even started a small family of their own, many years later. When the Marauders were whole again, including their latest addition of Fred Weasley, things seemed to be more homely. It was like nothing had ever gone wrong. In the end, all was well.