A Mathematical Approach to Psych

A Psych/Numb3rs Crossover

By RascalFlattsS

Disclaimer: I don't own Psych or Numb3rs. The characters are properties of their owners. This is not written for publication purposes.

Author's Note: This is a crossover of both Psych and Numb3rs. I just thought it would be interesting to write a story between these two TV shows because they are both in the same local area and they also both solved crimes in two different ways. Plus, both Charlie and Shawn are not just hot, but have cops (or FBI agents) in the family. Plus Charlie already doesn't believe in psychics (see Season 2 of Numb3rs "Mind Games") so I always wondered how he would respond to Shawn. Enjoy.

Also, this takes place during season 4 of Numb3rs and season 2-3ish of Psych.

Chapter 1: Let's Bring Out the Consultants!

It was a beautiful sunny day in Santa Barbara, California. Except for another dead body found on the beach. Normally, even that wouldn't have put too much of a damper on the day, except that it was the sixth body found in the L.A. suburb area in the past three weeks. Which could only mean a serial killer was out running around the L.A. which no one really wants to think about.

Santa Barbara Police were called along with local FBI agents. Chief Karen Vick of the Santa Barbara Police Department, along with Head Detective Carlton Lassiter and his partner Detective Juliet O'Hara were already on the scene when the FBI SVU pulled up.

FBI agent Don Eppes stepped out of the driver's side. He glanced over towards the dead body. His attention turned when he heard the door of the passenger's side opened.

Everyone who saw Charlie Eppes knew he was Don's younger brother. And despite the fact that they were so similar, they were so different. Charlie had dark, curly brown hair where as his brother's was straight. Charlie was a mathematical genus working as a professor at CalSci. However Charlie did share his brother's passion for catching criminals and for the past three years had used his mathematical skills to helping his brother put criminals behind bars.

But no matter how much Charlie worked with Don, Charlie was still Don's little brother and Don tried to shield Charlie from the many horrors of his jobs. And looking at dead bodies that were tortured defiantly counted.

"Charlie," said Don stopping his younger brother. "Why don't you wait here by the car?"

Charlie shook his head, "Don, you don't need to protect me anymore. I've seen dead bodies before.

"But this is different," said Don. "This is…"

Charlie cut him off. "Don, I've already seen the photos of the victims. And I personally want to catch this guy and the more information I have, the better my equations are and the sooner we catch the SOB. So, let me do my job." And with that Charlie pushed Don's hand off his shoulder and walked towards the crime scene.

Don sighed as FBI agents, Colby Granger and David Sinclare walked up beside him. "What am I going to do with him?" Don asked.

"I don't know," said Colby, "Have him do all your math homework for you?"

Don pushed Colby and the three of them started walking towards the crime sense.

Charlie arrived at the tape and started to walk underneath when a hand grabbed him and turned him around, pining him against a pole, pinning his arms behind him. The clipboard, pencil and calculator fell to the ground.

"What are you doing?" asked Charlie.

"You are under arrest for trespassing at a crime scene and for obscuring justice," said SBPD head detective Carlton Lassiter, as he cuffed Charlie, "You have the right to remain silent…."

"WHAT THE HELL ARE YOU DOING?!" shouted Don. He, Colby and David ran up to Lassiter and Charlie. "Who the hell are you?"

"I am Head Detective Carlton Lassiter of the SBPD," said Lassiter, showing Don his badge, "I am arresting this man for trespassing on my crime scene. Who the hell are you?"

Don whipped out his badge, "FBI agent Don Eppes. And you have five seconds to let go of my brother or so help me God…"

Lassiter looked from Charlie to Don, "Your brother? You brought your brother to a crime scene?"

"Charlie is a consult for the FBI," said Colby. He and David were holding Don back from killing Lassiter. "He's a mathematician at CalSci."

"A mathematician?" repeated Lassiter. "Does he have clearance?"

"The highest," snarled Don. "Now. Let. Him. Go."

Lassiter sighed and pulled out a key and un-cuffed Charlie. Don reached forward and pulled Charlie away from Lassiter. "Are you alright?" asked Don.

"I'm fine," said Charlie. He picked up the clipboard and calculator and walked under the crime scene tape. Don gave Lassiter a death stare and then followed closely behind Charlie.

Lassiter sighed and ran his hand through his hair. And he though Shawn Spencer was a pain.

"Don't worry about it," said Colby. "Charlie is Don's little brother and about a month ago, Charlie became a target in an investigation. He was actually run off the road by these guys and they almost killed him. Don's been a little overprotected over Charlie since." Colby held out his hand to Lassiter. "I'm Colby Granger and this is David Sinclair."

Lassiter took his hand. "Carlton Lassiter." And with that the three of them walked towards the crime scene.

Don kept glaring at Lassiter but didn't say anything as the three of them walked up and listen to Chief Vick fill them in on the victim.

"And Professor Eppes, what exactly will you do?" asked Vick.

"I am a professor of applied mathematics at CalSci," said Charlie.

"He is also an FBI consultant," said Don, continuing to give Lassiter an evil glance.

"We'll we appreciate all the help we can get," said Vick. "However, we already have a consultant that we work with. And at the moment, he and his partner have a hundred percent closing rate."

"You already have another consultant?" asked Don. "Who?"

Just then, a blue Echo pulled up to the crime sense tape. Shawn Spencer and Burton "Gus" Guster stepped out of the car.

Shawn Spencer walked up to the crime sense tape, lifted it up and he and Gus walked underneath it.

"Lassie! Jules!" said Shawn. "What do I owe the pleasure?" Shawn turned and saw Charlie staring at him. "Who are you?"

"Mr. Spencer," said Vick. "Meet Professor Charlie Eppes from CalSci. He is a mathematical consultant for the FBI agent. Professor Eppes, meet Mr. Spencer. Mr. Spencer is our psychic consultant for the SBPD."

A/N: Hope you like it so far! Especially the part where Lassiter tries to arrest Charlie! Please R&R and let me know what you think!