Sam awoke the next morning with a renewed sense of purpose. He had gone to bed feeling more depressed than he ever had in his life. He had lain in Charlie's bed, and stared at Charlie's ceiling and wondered if he would ever have anything for himself again. If he'd ever have a relationship that lasted more than three days again. If a woman would ever look at him and see him, and not whoever he had leaped into, again.

After two hours, he was absolutely bored with his little pity-party and he had to get up and do something. He started to paw through Charlie's math notes but, although sleep wouldn't come, he was too tired to concentrate on such complex ideas. He found himself, instead, perusing old yearbooks and photo albums. He didn't usually delve so deeply into the lives of his hosts. It seemed disrespectful to go through their personal things, even if he was already wearing their underwear. But this was no ordinary leap and Charlie was no ordinary host.

The father's name was Alan. The mother, Margaret, had been dead for a couple of years. He got all that from a program from her funeral Sam found. Charlie had apparently graduated high school at 13 in the same class as his older brother. Sam couldn't help but think of his own brother, Tom, whom he hadn't seen since he leaped into his unit to save him from dying in Vietnam.

Although Charlie was undoubtedly an accomplished mathematician, Sam found a box full of Don's box scores from playing minor league ball, and almost nothing about his own awards. My God, Sam thought, he must worship his older brother. Well, there was something Sam knew about.

He also found a bunch of photos of a pretty blonde. He gathered that the relationship was over, but the fact that it had happened at all helped bolster Sam's spirits. The world had, indeed, moved on without him. But not in a horrifying, robots taking over the world, science fiction movie way. Just in a normal way. People loved, people broke up, people died, people played baseball. There was comfort in the fact that the human race still functioned in roughly the same manner that he was used to. They just seemed to do it now with cell phones.

Sam had finally crawled into bed, exhausted. When Charlie's alarm blared, Sam had showered, dressed, and headed downstairs.

"Morning," Sam greeted Alan, who was in the kitchen.

"Good morning, Eggs?"

"Sure. Over easy, please." Sam took a seat at the table and pulled the newspaper towards him. More about the war. A story about a little boy who had been reported kidnapped, but who actually had been murdered by his foster family. It never ceased to amaze Sam how much and how little the world changed from leap to leap.

Alan set a plate in front of him. "I thought you liked scrambled."

Sam smiled. "I guess I just felt like over easy."

The phone rang and Alan went to answer it. A few moments later, he handed it to Sam. "It's Don," he said.

"Hey, buddy. You feeling better?" Don asked.

"Uh, yeah. Thanks."

"Great. Listen, we found another body. So, I'll have Colby bring by the data for you this afternoon when we get it all compiled, okay? I mean, more data means a better equation, right?" Don sounded overly happy and optimistic. Sam could tell he was hoping Charlie wasn't going to refuse to help him.

"Sure. That'll be useful. I, um, I guess, just have him drop them off at my office."

Don sounded absolutely panicked. "Your office? No, no, no. You're teaching today? No, you gotta do your thing. You gotta lock yourself in the garage and refuse to talk to anyone until you get this solved." Charlie sounded like a real barrel of laughs. "Listen, I'll call Amita and get her to have your classes covered. You just concentrate on finding the bad guy. I'm counting on you. Right, buddy?"

Amita? An image of the pretty Indian girl from the day before presented itself in Sam's mind. He wondered what, exactly, her and Charlie's relationship was. Also, Sam realized that Don was very aware of how hard Charlie tried to impress him and wasn't above exploiting it for his own purposes. And Don was also willing to remove any obstacles or distractions from Charlie's way.

"Okay. I'll just concentrate on your case today," Sam said, glad to get out of teaching any classes.

"Great. Call me if you have anything. I gotta go."

Sam hung up the phone and turned to Alan. "I'm going to work in the garage today," he said.

Alan nodded as he hung up the phone. "You're allowed to say no to your brother, you know," he said.

Sam entered the garage tenuously. It looked like yet another version of Charlie's office. It was as if the sheer enormity of Charlie's genius had filled his office, spilled over his bedroom, and, when that became over-full, to the garage. Nestled among the tools and the washing machine were chalkboards covered in the bounty of Charlie's mind.

"Sorry, buddy," Sam muttered, erasing the boards. "Hope you've got this written down somewhere."

He had discovered in Charlie's room a paper that Charlie had given at a math conference about the quantification of the actions of serial felons. Sam sat down on an old couch and began to read. Sam often wondered if he, singularly, had been chosen to leap or if he leapt merely as a consequence of his own actions. But the answer seemed clear at this moment. How many people could understand this paper, much less have the ability to apply it to an actual case? This task was set to him, and him alone.

Several hours later, Sam looked up from the chalkboard where he was making notes to find Al smoking a cigar. "How long have you been there?"

"Not long. I didn't want to bother you. Is that it?" He gestured at the board.

"Well," Sam said, not sure exactly how to explain things, "yeah. I mean, that's Charlie's equation but..."

Al clapped his hands and rubbed them together excitedly. "Good work, Sam, you did it! Now, just plug in the numbers and get ready to leap!"

"It's not that simple," Sam explained, a little bewildered by his friend's reaction. "And why are you so eager anyway?"

Al sighed. "You gotta leap, Sam. This guy in the waiting room is driving us all nuts. He didn't buy the whole 'kidnapped by aliens' story at all. He says our imaging chamber is underpowered. And he wants to re-index Ziggy's database. Gushie is ready to put a muzzle on him!"

Okay. Sam officially decided that he liked Charlie.

"But," Al continued, "he did come up with some good ideas for our holographic algorithm. Am I coming in sharper?"

Sam chuckled. "What are you, a TV program?"

Al considered it for a minute. "Yes. Yes I am." He stuck the cigar in his mouth and turned in a circle for Sam. "Well? How do I look?"

"Great. You're a shoe-in to win the swimsuit competition."

"Sam, I'm being serious! Now take that big beautiful brain of yours and find that bad guy!"

"You know, this isn't exactly as easy as it looks," Sam snapped, getting annoyed. "You have to analyze the data. Do you have any idea how complex this is? It probably took him weeks, maybe even months, to come up with this."

"Two days," Al interjected, consulting the handheld interface to Ziggy that he always carried.

"Two days!" Sam practically yelled.

"Well, not two days," Al corrected himself.

Sam felt a little better. Two days, indeed. Not even Charlie Eppes was that smart.

Al squinted at his interface. "He did it in one day. But he had to re-work it for two hot zones, and that took the second day."

Now Charlie was starting to tick Sam off.

The door opened and Amita entered. She dropped her things on the couch and stared at Sam, hands on her hips. "You are aware that I'm not your assistant anymore, aren't you? I mean, that hasn't escaped your attention?"

Sam had no idea what she was talking about. He shook his head. "No, of course not."

"Then why, exactly, am I getting calls at 7am from your brother telling me to cancel all of your classes?"

"I'm sorry," Sam stammered. He tried to ignore Al, who was circling her, inspecting her from every angle. "He should have called my new assistant. He didn't have her..."

"I thought his name was Fred?" she asked.

"...his number," Sam replied.

"Well, I called Fred and told him you were working from home; I got all your classes covered. And I rescheduled your meeting with Dr. Hicks until Thursday."

Sam smiled. "Thank you."

"No problem," she said, shrugging. She walked over to Sam's work, examining it. Sam got the distinct impression that, unlike Al, she knew what she was looking at. "Why are you revisiting these old equations?"

"I'm working on a case for Don." He wasn't sure how much he could say. Talking about open FBI investigations to someone without the proper clearance seemed like a very bad idea.

She glanced at the file which was lying open on the table. Sam quickly shut it. "Okay," she said, not acting offended by his action. "But it's like you're trying to re-derive them."

"Well, I think there's a flaw."

"A flaw? Charlie, there's no flaw. We tested it on solved cases, remember?"

"I know," Sam lied. "But this equation is pointing us to Martin Brewster. And I think he's innocent."

"Based on what?"

"A hunch," Sam said, never sure how to answer those types of questions.

She rubbed her forehead. "I don't understand. The equation doesn't work like that. It doesn't give you a person. It gives you the probability that the killer lives in a certain area. The hot zone."

Al was messing around with the Ziggy interface again. "The hot zone that Charlie's equation came up with was a huge estate that Brewster's parents owned."

Sam rubbed his hand over his mouth, thinking. "The hot zone was too small," he said.

"What?" Amita asked.

"Um, I said, the hot zone I'm getting is too small."

"That would be a good thing, Charlie," she said, laughing. "Less ground for the FBI to cover. Listen, just give the results to Don and let him have the hunches, okay?"

"Lunch is ready," Alan announced, barging through the door. "Oh, Amita. I didn't know you were here. Are you hungry? It's nothing fancy. It's just tuna fish."

"No, thanks," she said, gathering up her backpack and a few other odds and ends. "I have to get back to campus. I just came to get Charlie's lecture notes. Someone has to teach his classes."

"Help yourself," Sam said, pointing to the satchel.

She retrieved the notes and started to leave. "Nice to see you again," she said as she squeezed past Alan.

"Nice seeing you again, too," he said, smiling. Alan watched her walk to the driveway and turned back to Sam, wiggling his eyebrows. "What were you two talking about?" he asked.

"Math," Sam said flatly.

Alan looked disappointed. "Math is not going to get me grandchildren."