Watched Tick Tick Tick this evening, and just had to imagine what was going on in their minds during this episode. I don't own anything about Castle, outside of my own imagination.

Italics are the thoughts in their heads.

Castle and Beckett strolled down the hall to autopsy, discussing the morning's events. "You know Kate, I can't believe I didn't hear anything this morning." He sighed, "I don't get it. I should have heard him. He could have tried to get in, and I would have been caught with my guard down." Frustrated he hit his hand against the wall. "I'm sorry, I let you down."

She stopped, and grabbed his arm. "Castle, look at me." She waited until he turned her way, those blue eyes intensely gazing back at her. She could see his frustration. "Castle. . . he just wanted to play the game. He's showing me he knows where I live, and thumbing his nose at us. We'll get him." She leaned in, "We will get him."

They shared a smile, and his gaze relaxed. The frustration faded slightly, and his smile reached his eyes. Nodding at her, Castle pulled open the door to Lanie's domain.

Lanie turned as they approached, a wicked glint in her eye. "Hey, heard you two were making pancakes when the body dropped." She teased. A quick laugh escaped, as she saw them both roll their eyes. Look at you two, even reacting the same way. Sweet!

"Nothing happened." Kate swore.

"Right," Lanie chuckled. Back to business, she read out the letters, but Kate cut her off.

"Burn – " she turned to Castle. "Nikki will burn."

Castle felt the concern growing, and muttered, "Well, that's chilling."

The three talked as they reviewed the results, with Lanie describing the formaldehyde. Kate agreed, "That's from the killer. He left it at the other scenes as well."

Lanie clarified with her next words, "Not traces. It was under her fingernails, in her hair." Castle and Beckett both focused on her words, turning them around in their minds. As one they turned to each other, saying "She's a taxidermist".

Lanie grinned, gotta text the boys about this – look at them. "Ah, it's so cute the way you two do that." She grinned even wider as they turned to her in synch with scowls. "Really, just saying."

After the events of the day, ending with the murder suspect in the morgue, Beckett and Castle left the precinct. "Tomorrow?" he asked.

"Tomorrow." She agreed, and they went their separate ways.

Castle relaxed at home, reviewing the crime scene details. He had gotten into a habit of reviewing photos and notes after cases were closed. You never know what ideas I can pull from here for the story.

Alexis walked in, pulling his attention. "Hey, " he murmered, "I thought you went to bed an hour ago."

She leaned over and looked at him. "I did. I couldn't sleep." She realized what he was viewing, "I thought the case was over". Concerned she looked at him. She found him staring at cases into the long hours of the night often, and knew this case concerned him.

Rick attempted to reassure Alexis with a gentle voice, "It is. Wrapped up all nice."

"That's good, right?" she asked, windering what she was missing.

"Yes. In a book, that's a good thing." He agreed, "but in real life – nothing is that neat." He tuned into her, realizing she was concerned. "What's got you still up?"

Alexis frowned slightly. "It's Gram. I can't believe she's leaving. I mean at first, I couldn't imagine her around all the time. Now, I can't imagine her being gone."

Rick leaned forward, reassuring. "Listen, it's a fact of life. People we love leave us. Unless you chain them to a radiator, which for some reason is illegal." He joked, coaxing a grin from his daughter. That's my girl – gets her dad's humor! "Knowing her, she'll be back in six months."

Martha glided into the room, making an entrance as only shoe could.. "Oh good, you're up. I need your help, deciding what to take. I need to get my bags down. Richard could you give us a hand?" she swung around, expecting them to follow along.

Castle stopped mid-stride. Lightbulb! Oh, wait a second. "A hand. . . ." he reached back to the pictures from the crime scene. "The bruising pattern on the second victim. The killer used his left hand! His handwriting – look at the slope on the four, the six" He felt panic gathering in his belly. Oh no, Kate! I'm wrong, I'm wrong.

"So, he was left handed," Martha commented, wondering what tangent her son was going onto now.

Alarmed, he continued. "Ben Conrad shot himself with his right hand. If the man in the window was Ben, he would've shot himself on the left side. Ben Conrad didn't kill himself. He was murdered by the man in the window. Ben's not our killer. The real killer was just playing with us." He couldn't breathe. Beckett!

Alexis stammered, "But, the evidence. . ."

He kept going, moving around the room. "It was planted there to lead us to Ben. He wants us to think it's over. He wants us to drop our guard." He couldn't get the words out, realizing Kate was still in danger. "Nikki will burn. . . Beckett. . . "

Martha gasped, "Oh god". She realized what Rick was saying. It was Kate who was still a target. He grabbed the phone and dialed Kate immediately. Answer the phone, answer the phone darn it!

"Montgomery took the detail off her place. She's alone" His call was not answered. He panics now, trying to get his bearings. He has to get down there to her house. "She's not picking up. Call the precint. Tell them to get over there right away." He runs to the door "Tell them we were wrong. The killer is still alive!"

He stares intently at Alexis as she follows him, his love for her evident in his gaze and his words. "You lock this door behind me. Don't let anyone in."