BtVS by Whedon and Mutant Enemy. Star Trek:TNG by Roddenberry and Paramount. Happily taking advantage of a Joyce/Mystery Guest FFA-Pairing ;)
Big shout-out to Bureau 13 here, though it's reversed in a different way :)
According to their tricorders, the warehouse practically gleamed with blood.
They followed a particularly striking trail of droplets to a darkened corner, and a dead body in a wheelchair.
There was a huge, barred cage to the left of the body. On the ground, chalked around the prison, was a square and the word 'Inbox'.
The occupied wheelchair sat in the square marked 'Outbox'.
Beverly's readings confirmed that the body had been drained of blood and that an odd anti-coagulating agent had been at work within the tissues of the neck.
Riker grimaced, commenting how that changed his theory that the vampires on the tape were somehow metaphorical.
Beverly was about to reply when she heard a rustling sound.
It wasn't coming from the body... There, against another wall, was a small birdcage.
Riker followed her across the room as she got a better look.
The animal was fluttering weakly.
"Poor half-starved thing," she muttered as she trained her tricorder on the little bird. "It's showing definite signs of malnutrition."
"Yeah, maybe if you fed it more often, that wouldn't happen," someone answered.
They spun around and found themselves face to face with a gaunt and now, very shocked, vampire, facial ridges and all.
The twisted humanoid did a double-take.
"You're humans!" he growled menacingly. "You're, you're not supposed to be in here! I'm going to-"
A phaser blast caused him to fall to the ground heavily.
"Even though, these guys are apparently the 'enemy'," Beverly cautioned. "Let's keep our phasers on Stun, until we find out more about this place."
Riker agreed wholeheartedly.
Two vampires were standing guard outside, on either side of the warehouse doors. They did not budge an inch when the doors were slightly opened.
When an unconscious body was thrown out of the warehouse, skidding across the ground between them, they looked at each other.
They turned around and stuck their heads into the opening, only to be met with phaser blasts directly to their foreheads.
The two Starfleet officers stepped over the bodies and began to explore Halloween in Sunnydale.
Angel was sorry he had to lead the way. At the current point in time, he'd much rather be a single step behind, lost in his own thoughts.
Oh well. Eyes front, to the side, above, scanning for monsters.
Ears perked, making sure the now silent Troi was keeping up her steady pace.
He'd thrown her off-balance, and done it well.
Now if she'd keep quiet until the spell wore off... Life would be good.
He'd been in a twenty-year funk for a mistake involving death and blood and only really snapped out of it when a demon called Whistler had slapped him in the face with a purpose, less than a week before Buffy had been called.
Before that, however, there had been somebody... Something, really.
For about five years in there, his relatively homeless self had a companion in the form of a possessed TV.
The parasite had fed off him, bombarding him with sights and sounds, dulling his pain.
It had arrived during the third season of The Next Generation and, amid many other programs, caught him up with the earlier Star Trek episodes through reruns.
Shortly after the show's finale, the parasite had reached the end of its own lifespan and... expired in a puff of flame and shattering glass.
He'd buried the empty shell in an act of catharsis, considered moving on, but regressed instead to his lonely and smelly funk.
Angel came back to the present, shaking his head.
She was a walking reminder of a low spot in his life.
Well, at least he now knew what an alien smelt like. Of course, he wasn't exactly in a place to tell how much of that was her half-human genetics and how much of that was just from her being born off-planet... And he was really hoping he wouldn't have the chance to compare her scent to the rest of her crew.
Her powers had a small chance of coming in handy, but he was mainly keeping her with him to protect whoever was trapped inside the costume.
If only he could somehow get her armed-
He paused, turning around, because Deanna had faltered in her steps.
He opened his mouth, to ask what was wrong, but then he heard the scream...
In the darkened bedroom, the woman's scream was abruptly cut off as her lungs filled with blood and her eyesockets exploded from the pressure building within.
She never even got to see the face of her attacker.
Deanna Troi panted out an explanation for the shock that had run though her. "Someone was just killed and the attacker, a dark patch of rage and... It's still inside the house!"
"Come on!" Angel yelled as he raced up the steps.
He hesitated at the door, but, when met with no resistance, he entered the house.
Troi followed behind, giving him directions needlessly. He could smell the blood.
He ripped a leg off a banister in passing.
They found the horribly disfigured body easily enough, the woman swelled beyond all recognition from an immense build-up of fluid.
Dark marks had been bored within her neck.
Her attacker was nowhere to be seen.
Deanna explained how she felt a miasma of rage stirring in an empty corridor of the bedroom.
Angel didn't believe her. She insisted.
He told her that he could smell nothing, hear
She told him he was wrong.
They actually got into a shouting match.
"Listen, there's nothing here!" he finally yelled, poking the corner with the stick to demonstrate.
The heavy wood was pulled out of his hands and flung across the room. Angel didn't have time to recover before a heavy blow to the chin knocked him off his feet.
The battle was furious, the enemy was invisible, but Angel had a friend at his back...
The real trick was: not letting go.
When the unseen enemy had been knocked out and Angel still couldn't smell
it with his keen senses, he turned around and began rooting through a dresser.
"What are you doing?" Deanna asked, bewildered.
"Here," he announced, withdrawing a small hand mirror.
Sure enough, the unconscious creature had a visible reflection.
It was a horrible mass of gristle and veins. The limbs bent awkwardly. The less said, the better.
"My guess is that someone had a skinned-man or an inside-out-man costume and decided to add a pair of fangs to it..."
"Here," he announced, carefully pulling back the thing's lips.
This revealed a roughly normal set of human teeth, with the exception of the fangs coming up from the bottom jaw, and the fact that the entire set looked like it had been stuck in upside-down.
"He was turned into a 'reverse vampire' with most everything about him, sight, smell, sound, somehow... well... gone. Except for his reflection in the mirror, and his reflection on your mind... Thanks."
Deanna half-heartedly returned Angel's grin. She'd seen the thing's mouth in the mirror, but hadn't seen Angel's hand...
She kept it to herself, for the moment.
On the street, Riker was having a grand old time pointing out the obscure costumes.
There was a miniature house hobbling down a corner. It was wide. The bricks were painted nail-polish pink. Human feet sticking out underneath had been forced into a tiny pair of blood-red high-heeled shoes.
"Yes, she's a brick house," Riker chortled, humming a few bars.
He knew a wide range of music.
A cat-headed woman ran by in a saloon dress.
"Let me guess," Beverly laughed, still carrying the bird and the small cage. "Miss Kitty."
They walked on a bit more, before Riker shot out an arm and halted Beverly's path.
She frowned, but watched in silence as a robed figure crossed the street ahead of them.
"Who was that?" she asked, when the apparition had passed.
"Someone's twisted idea of Thelonious Monk," Riker growled in outrage. "Let's get out of here as soon as possible. This place just became a lot less funny."
Having carefully tied the creature up, Angel and Troi carried it out of the house and down the block, before dumping the heavy thing in some bushes.
They walked on.
To help fill the silence, Angel explained how they were going to the home of the Summers family. "I'm really hoping to find my friend, her name's Buffy, safe, out of costume, and trying to explain things to her mother."
Joyce Summers was having a grand old time at the masquerade ball.
The guests had arrived in their most elegant clothes and, from the large tables at the entrance, selected a mask to wear.
Almost no-one had brought their costumes from home.
Only one man had bought his costume at Ethan's.
"May I have this dance, my lady?"
Joyce spun around to take in the short, brown-haired man in the tight golden uniform.
"I have found myself alone, in this strange land, and I have chosen you, as the most beautiful one here, to ask questions of. Please, let me bask in your presence."
She smiled underneath her blue and feathered mask and reached out to take his hand. "Absolutely, Mr. Kirk."
His eyes widened slightly, but he grinned as he whisked her out onto the ballroom floor.
"Tell me," he asked, as they twirled. "Is this Earth?"
"For you, my finely costumed friend," Joyce answered, with a twinkle in her eye. "Why not?"