What began as an idea for a throwaway joke in my Monsters vs. Aliens fic implying that MvA and Twilight exist in the same universe has grown into an idea for a full-blown crossover. So, here it is…

MONSTERS VS. VAMPIRES

If you're unfamiliar with Monsters vs. Aliens… well, there's a hell of a lot of exposition here in the first chapter. If you're unfamiliar with the Twilight saga, you're pretty much screwed. I suppose that's the problem with making a book/film crossover… a hell of a lot more people watch movies than read books. Anyway, for a bit of introduction you might want to read my short MvA fic, "The Good Life". This one is an interesting change for me, as I can do various first-person perspectives now. I will make an effort to alternate between the POVs of Twilight and MvA characters equally; the character narrating the chapter will have their full name printed directly below the chapter title.

I wanted to include the Maximum Ride series in this, in a kind of three-way crossover of the three things that have greatly inspired me this year, but as I have not yet read the fifth book of that series I'm going to have to wait a while before splicing that one in.

Chapter 1: Wake-Up Call

BELLA CULLEN

Edward and I looked down at Renesmee, sleeping peacefully in her bed. Two years old now, she appeared to be just on the verge of hitting puberty. Edward stiffened suddenly.

"What's wrong?" I asked.

"Alice is here," Edward said. "She's pretty upset about something… there's some kind of danger coming."

We left the house and ran down the beach of Isle Esme to intercept Alice. She was carrying a heavy binder in her hands… or what would have been a heavy binder in the hands of a mortal.

"What's going on?" Edward asked.

"The Modesto Monsters are coming after us," Alice reported. "They're coming here, to Isle Esme, searching for us, to determine if vampires are a threat to human society."

"Who are the Modesto Monsters?" I said blankly.

"The Modesto Monsters," Alice explained patiently, "are a group of monsters who live in Modesto, California. The ones who helped combat the alien invasion."

I gaped. "How long have we been out here?" I wondered. Glancing at Edward, I could see in his eyes that Alice was dead serious.

"You're not worried," he noted.

"No," Alice said. "I think we can be diplomatic about this. We can explain to them about vegetarian vampires."

"What about… regular vampires?" I asked.

"Explain to Bella who the monsters are," Edward said. "I see you've prepared a picture show."

Alice shrugged. "Oh, you know how I love explaining things," she said.

"No you don't," Edward and I retorted in unison.

"Well, I like explaining this," Alice said. She opened the binder and began to tell a story in a haunting voice. "1952. A British scientist attempted an experiment that would give humans the relative longevity and invulnerability of a cockroach. His first test subject was himself, and the experiment had a minor side effect, and he is now… Dr. Cockroach, Ph.D." She dramatically unfurled the first photograph. It was a man in a white lab coat, with an enormous cockroach's head. My sensitive eyes could tell that the photo was not at all tampered with. "His intelligence is unaffected, and he is still the world's greatest problem solver and mechanic. He is only slightly addled by a roach-like appetite.

"Now, 1958. Researchers at a snack food company were using unbalanced chemicals in their testing. One of these tests, a chemical-filled ranch dressing injected into a genetically enhanced tomato, resulted in a conscious gelatinous mass known as Benzoate Ostylezene Bicarbonate, or B.O.B. if you will." She held out the second photo; a man-sized blob of blue goo with a single red eye and a wide, grinning mouth.

"B.O.B.?" I repeated with a laugh.

"Don't laugh," Alice said sternly. "It's completely indestructible. I don't think that even a vampire could harm it."

"How do we fight something invincible?" I wondered.

"We don't," Alice said. "I told you, we're going to be diplomatic. If it does come to a fight, though, I think that in a fair fight a vampire could fight B.O.B. forever. His only real weapon is to ingest someone, and since we don't need to breathe we could break free. I suppose his weakness is a tendency to forget what he's doing… but that doesn't matter. Shall I go on?"

"Please."

"Okay. 1965. Arctic explorers discovered the frozen carcass of a creature with genetic connections to both fish and the great apes. Dubbing it the Missing Link, they took it to a science lab, where it thawed and escaped. After a while it learned to speak and is now fairly civilized." She held up the photo. The creature was covered in equal parts with scales and hair, with a dorsal fin and fish's tail but the overall shape of a gorilla. "And then, 1969. In Tokyo, a caterpillar was enveloped in nuclear radiation and grew to 350 feet tall, as well as gaining an advanced, if somewhat childlike, intelligence and phenomenal eyesight. It's called Insectosaurus. It remained a larva for nearly forty years, until last year when it was wounded and revived as a giant butterfly." She showed two photos, one of the larva and the other of the butterfly, surrounded by buildings for comparison.

"Question," I said, raising a hand.

"Can't a girl finish a story? What?"

"If these monsters were created in the fifties and sixties, why have we never heard of them before now?"

"They were locked up in a secret government prison," Alice explained. "They recently obtained their freedom in exchange for fighting off the alien invasion."

"Yeah, what's that about an alien invasion?" I asked.

"One story at a time," Alice said irritably. "Finally, 2008. A young woman named Susan Murphy was hit by a meteorite and absorbed an extraterrestrial element called quantonium, which caused her to grow to five stories tall, possessing immense, disproportionate strength." She held a photo of a white-haired woman sitting on a semi truck, her weight sufficient enough to dent the truck's trailer. "Her monster name is Ginormica, but most people still call her Susan.

"Okay, here's my plan. They'll arrive on the island in a few short minutes. I can't tell what they're going to do when they get here, because they haven't the faintest idea what to expect. So the best we can do is reason with them."

"Why are they coming again?" I asked.

"The government has decided to investigate the existence of vampires, believing that the monsters may be able to harm us while conventional weapons cannot. The same principle that led them to use the monsters to fight the aliens, which was completely successful."

"Uh-huh. Tell me again about the aliens."

Alice looked up. "No time," she said. "They're here."

Edward and I followed her gaze. High above our heads we saw what could easily be mistaken for a fuzzy red butterfly flying a small distance above our heads. Our vampire vision, with its heavily improved depth perception, could tell that the butterfly was thousands of feet in the air.

"Insectosaurus," Edward whispered.

"Carrying the other four," Alice added. "They'll spot the isle any second. Anybody have a white flag? We're sitting ducks. Ah, here he comes…"

"How are you so attuned to these monsters?" Edward asked.

"I'm not," she said. "I was just keeping an eye on you when I saw the monsters landing here… I had to back up a bit. It was hard, since I've never met them. But with a bit of digging, I figured it out."

Insectosaurus was now nearly upon the island. It was something to behold; a quick measurement with my eyes confirmed Alice's statement that it was 350 feet tall. Living creatures should not be that big, I thought. My quick mind was nearly overwhelmed. The colossus landed in the shallow water, which barely came up to its knees, and the other four monsters jumped fluidly off its back and marched toward us. The cockroach-man was the smallest of them, and even he was larger than any human. I hadn't felt this kind of apprehension since my human days; though the Volturi had been frightening, at least I knew what to expect from them. I had no idea what to anticipate from the Modesto Monsters.

"Good afternoon!" the blue goo said. "Seen any vampires around?"

"Okay, conference," the Missing Link said in a gravelly voice. Its English was flawless, but my sensitive ears detected subtle hints indicating that it had lived much of its life without speaking. "I think the job of greeting people should go to someone besides B.O.B. Anyway, I think these are the vampires we're looking for. Look at 'em glitter. That's just plain freaky, and that's coming from me."

The gigantic, platinum-haired woman approached and crouched down to get a better look at us.

"We know," Edward said. "You're here to determine if we're a threat to human society. Let us explain, please."

"How did you know why we're here?" the woman demanded.

"Later," Edward said hurriedly. "Listen, the vampire world has rules… just one, actually. Keep the secret. Our existence can't be confirmed by humans. If you tell anybody what you see here, the vampire royal family will kill us, and you. We can tell you, since you are, in clinical terms, monsters, but you can't let the word spread beyond the five of you."

"So I take it you are a threat, then?" Dr. Cockroach said suspiciously.

"Not us," Edward said hurriedly. "We're vegetarian. We'd never hurt a human."

"Vegetarian, huh?" the Missing Link said, impressed. "That's pretty cool. Insecto here is vegetarian. Ever since his eighteenth birthday party in the prison back in '87. He ate the whole cake before we could tell him there was a stripper in it. Scarred him for life."

"We're not vegetarians in the human sense," I offered. "It's just an inside joke among our family. We drink the blood of animals instead of humans."

"You seem to be implying that there are vampires who do feed on humans," Dr. Cockroach said.

"Most do," Edward admitted. "Our immediate and extended family are the only vampires we know to care for human life. More or less all other vampires prey on humans regularly."

"Well, thank you for your honesty," Dr. Cockroach said. "Tell us where to find these man-eaters, then, and we'll let you and your family go on your way."

I shrank into my cat-like fighting stance, and Alice and Edward followed my lead. The monsters recognized our stance and also tensed up.

"Man-eaters or not, these other vampires are our brethren, our kin," I said. "You can't just go around exterminating them for their very nature."

"We are dedicated to the protection of this planet," Ginormica shot back. "If there are vampires in the world, we need to save the people from them."

"And this is the reason for your creation?" I guessed. "To defend the Earth?"

"No, that's just our job," she clarified. "We're free to do whatever we want. But we love this planet. It's our home."

"We don't look to destroy innocent people," Dr. Cockroach said. "We're not barbarians. Well, except for Link. But we won't harm you, if you're honest when you say you don't hurt humans. But we feel obligated to keep humans from harm. Tell us where to find these man-eaters, now, or we shall take the answer from you by force."

"All over the world," Edward retorted. "It's a whole species. You can't hunt them all down."

"What about this royal family?" Dr. Cockroach asked.

"I wouldn't recommend that," Alice said. "If you destroy them, you destroy the government that keeps vampires from coming out. The world will fall into chaos."

The monsters exchanged a few glances. "I see there's a lot we have to learn about each other," Dr. Cockroach said.

I considered the last time I had heard that phrase uttered, or something like it, and wondered whether I should be feeling a chill up my spine.