BTVS Xover with Firefly - BTVS season 5, Firefly season 1 (Out of Gas) ... Spike jumps into the portal and is transported into OUT OF GAS's Serenity ship with no air, after Mal has been shot. Mal is transferred to Sunnydale and is found by

Willow/Buffy/Xander/Giles/Anya/Tara

OUT OF GAS

Sunnydale, California…

Spike turned to Buffy and Dawn. "I have to do this." He told them.

"Spike, no you don't. Summers' blood is the only thing that will close the portal. It has to be one of us." Dawn explained.

"Pet, blood is the only thing that matters. But it's not just your blood; it's anyone's. It's everyone's. Blood is quite obviously a vital part of my life, being a vampire and all. That means I have to do this and you have to let me. Just stand back."

Dawn stepped up to Spike as he turned his back and placed her hand on his shoulder. "Don't." She begged, tears streaming down her smooth cheeks.

"Pet, let me do this. Always remember that I love you and that I love Buffy." Spike said without turning around. He knew if he looked back one more time he couldn't do it; he couldn't leave the woman he loved and the girl he lived to protect behind. But he had to, so he took a step back as Buffy pulled Dawn away from him.

"Dawn, there's no stopping him." Buffy whispered as Dawn gaped in horror at the swirling portal before her. Buffy swallowed the lump in her throat and fought to hold back tears.

Spike took a run-up and leapt into the portal, his eyes clenching tightly shut at the last second. God, why was he doing this? Dawn spun around and began uncontrollably crying into Buffy's shoulder. Buffy was lost for words. She couldn't comfort her sister because she couldn't move. Spike had just died for her. He'd just died for Dawn.

In the portal, Spike felt himself burning. He felt an intense heat and felt as if he would fall to dust in seconds, but then it all stopped. He looked around and there was nothing but white. Nothing but bright, bright white everywhere. He was still falling; he could feel himself falling. He was just… nowhere. Then it all disappeared and everything went black.

Serenity…

Mal had ordered the men to leave Serenity, taking from them the part he needed to fix his ship. But could he make it to the engine room? Could he get there in time to save his precious ship? He didn't have a chance to move, as he felt an intense heat around him. With the lowering air supply that couldn't be good for him or his ship.

A swirling blue and white vortex appeared before him, screaming and whirring so loudly that he had to cover his ears, struggling to stand after his injury. The gunshot wound to his stomach was still bleeding terribly, with his quivering hand hovering above his shirt.

As he looked into the swirling mix he tried to figure out what it was. He didn't know of portals existing at all, besides in old stories his folks used to tell him as a child. He was damn sure that's what he was looking at, but didn't know where it led or why the hell it was on his ship.

Suddenly, all his thoughts and questions were disregarded as the portal grew and swallowed him inside. He screamed, crying out in pain as the heat was unbearable.

Strange, he could hear another scream other than his own. He hadn't realised that his eyes were clenched tightly shut, so he opened them. It was just in time to see a man shoot past him down the tunnel towards Serenity. The blonde hair wasn't what caught his eye; it was the black clothing against the white vortex. The man must have seen him too, because at the split second they passed each other his eyes were wide with fear. Mal could tell. The man must have seen the same fear in Mal's eyes too, because it explained how he felt.

Suddenly there was nothing to feel; the heat was just gone. There was nothing to see except a vast white… everywhere. He was alone, injured and still falling through a tunnel to only God-knows-where. Then it all went black.

---

Back on Serenity, Spike felt himself being projected out of the portal, and hitting something hard. He saw only for a split second a lot of grey and metal before he was knocked out.

He woke to find himself lying on a metal floor. He opened his eyes and looked up to find himself inside a large hangar-type structure. He was lying on his back, staring up at the large empty room wondering where the hell he had been thrown after jumping into the portal. He remembered what had happened, dying for Buffy and Dawn. He loved Buffy, but never had a real chance to show it until now, until he gave up everything for her.

Spike painfully got to his feet and investigated his surroundings, not knowing about the lowered air supply on the ship. He didn't even know that he was on a ship, so went exploring to determine exactly where he was.

Mal's crew soon returned to help fix the ship, but in that time Mal was in another place and in much worse shape and a lot of pain.

Sunnydale, California…

Mal was dropped out of the portal about three metres above the ground and was abruptly stopped as he landed on debris from a fallen building. He screamed out in pain for only a second before he was found by Buffy and her friends after their fight against Glory.

Buffy, Giles, Dawn, Willow, Tara, Xander and Anya gathered around to see who was lying on the rubble. It wasn't Spike, so where did he go? More importantly, who was this man?

Mal looked up at the people staring at him, and tried to get up. "What the gorram…?" he began, still struggling and trying to wriggle away from the strangers towering above him. "Who are you…?" he breathed before passing out.

"Who's he?" Buffy asked after a suited silence, perplexed. The man lay motionless, a perfectly still body dressed in reasonably old-fashioned-looking clothes. And tight pants.

A/N: I had a strange idea and decided to give it a try. I've got another BTVS season 5/Firefly crossover idea, but we'll see if anything comes of that. Reviews on this one please? Maybe I'll update if people are interested…