Back at the office, Beckett sat deep in thought. She kept sneaking glances at Castle, who seemed to be sitting and…well, staring at a wall.

"Can I ask what you're doing? You've been sitting there all morning. Staring at the wall." Beckett got up and moved nearer to Castle.

He grinned, "Well, the way I see it – walls are going for thinking. They're plain and empty and don't disrupt your thoughts."

Beckett tried not to laugh, "That would be quite a good answer, Castle, but there are pictures on this wall. How does that make it plain?" The giggle left her mouth.

"Aha, there she goes, laughing again. Sometimes creativity is inspired by simple things. And these pictures, well, they're not simple, but they're nice."

At this, Beckett snorted. "Nice? Are you feeling alright? They're photos of the building construction."

Castle tapped his fingers against the wall. "Yes. And that's just what I'm looking for. Or should I say, looking at." With a quick sideways grin, he shuffled his feet and resumed his staring. Beckett returned to her desk, shaking her head.

Esposito jogged into the office, waving a page of paper.

"They got her ID – Maria Turnell, 34 years old. Lived just a few streets from her. No criminal record, unless you count calling 911 for "being lost."" Esposito handed the page to Beckett, then whispered to her. "Any reason why Castle's staring at a wall?"

"Apparently it helps him think," she whispered back, trying to withhold the laugh in her mouth. Unfortunately it escaped into a muffled snort-like laugh. Esposito roared with laughter and Castle turned around to see what the commotion was about.

"Ooh. Funny murders, I like them," he paused, "No, wait. You're laughing at me, aren't you?" Castle tried to keep a straight face, but couldn't and when Ryan walked in 5 minutes later, he was greeted with the scene of his three workmates hunched over a desk, howling with laughter.

Beckett stood outside the dark entrance to the house of Maria Turnell, the steps cracked with paint peeling. A cold wind whipped through the area, blowing paint chips to the ground.

"Okay," deep breaths, Beckett murmured, rubbing her arms to warm up, "you can do this. You've done it heaps of times before."

"Talking to oneself is the first si-"

"First sign of madness, yeah, I know," Beckett sighed, not turning around to look at Castle.

"Wow. You actually listened to me," he sounded awestruck.

"Well, it's a little hard not to when you never shut up," she allowed herself a quick grin, straightened her jacket, slowly raised her hand and knocked on the door.