A/N: A Batman/Halloween crossover based of the 2004 show 'The Batman'. Except for Harley, She's from the older series (Example, the episode 'Mad Love').

15 years ago Michael Myers killed his Mother's boyfriend, his older sister, and her boyfriend on Halloween night, but left his little sister Angel unharmed. He has been in Arkham Asylum ever since. He has been place under therapy of Dr. Samuel Loomis and his assistant, a recently rehabilitated Harley Quinnzel. Then he breaks out. Meanwhile Barbra Gordon lies her friend, Laurie Strode, for the reason she can't help babysit Tommy, because she'll be with Batman and Robin. As the streets of Old Gotham run red with blood, Batman must ask himself, is he willing to break his policy in order to stop Michael? And if not, what will happen to Angel when Michael finds her?

Batgirl and Robin are a bit older in this and they are together.

HALLOWEEN

Prologue

Halloween 1998

Old Gotham, 11:30 P.M., October 31st 1998…

Michael Myers sat at his kitchen table eating the little bit of candy he had since his older sister wouldn't take him trick or treating. Not to mention his Mother's boyfriend was a complete asshole.

Suddenly something inside Michael snapped. It couldn't be explained, but his brown eyes turned to black as he put on his clown mask.

He grabbed a thirteen inch kitchen knife and some duct tape out of a drawer. Then he approached the passed out and drunk form of his Mother's boyfriend, Robbie White.

Michael taped him to the couch and taped his mouth shut. He didn't wake until Michael slit his throat. His scream was muffled by the tape. Michael just watched as the light faded from his eyes.

Soon after that his sister's boyfriend, Steve Haley, came down stairs. Michael grabbed an aluminum baseball bat and snuck up behind him. Michael swung as hard as he could hitting him on the side of the head. The moment he hit the floor Michael hit him again, and again, at which point his face caved in, Michael continued to hit him until his head was reduced to a bloody pulp.

Michael climbed the stair and head to his older sister Judith's room. In the hallway he found a greyish white mask with brown hair and what looked like cracks across the face. He traded his clown mask for it. Then he entered Judith's room.

Judith lied on her side in a nightgown, her back to Michael. Michael gently ran his bloody fingers across her thigh causing her to giggle.

"Steve stop it." She said playfully, "You've had enough for one night." She said and sat up.

"Michael?" she asked, "What the Hell are you doing in here?"

"…"

"Hey! Didn't you hear me? I asked what the fuck are you doing in here!?"

Michael responded by stabbing her three times and leaving the room.

Judith, weakened from the pain and blood loss crawled through the hallway hoping to reach a phone until Michael reappeared behind her. He walked up next to her and she looked at him with fear filled eyes before he stabbed her fourteen more times.

Then he moved to Angel's room. After he walked into Angel's room he sat his knife on her dresser and removed the white mask, his eyes brown again.

"Hey Angel." He said as he picked up his little sister and kissed her forehead, he then carried her, his mask, and his knife out of the room.

Sirens blared as the police and paramedics investigated. Three dead and only one possible suspect.

"I'm sorry Mrs. Myers." Loomis said, "But we have to take him away."

"Where?"

"A low security mental hospital, he'll be fine."

11 months later…

Dr. Loomis looked at the security footage, there was no mistake, Michael killed the nurse for no reason.

"What do we do with him now?"

"There is only one place where we can keep him away from other's indefinitely until he's stable."

"Where Dr. Loomis?"

"Arkham."

A/N: The Opening.