As soon as they had the number written down and had checked it, Castle and Beckett headed out of the interrogation room and back out into the bull pen. Gates, Esposito and Ryan all filled out of the observation room and joined them.

"Good job Detective, Mr Castle," Gates congratulated them.

"Thank you sir," Beckett accepted.

"So who's going to make the phone call?" Esposito asked, "Now that we have a number."

Beckett and Castle shared a look. "I rather think that Detective Beckett should make the call," Gates suggested, "After all she was the one who got the number."

"Castle helped," Beckett pointed out."

"That he did," Gates agreed, although she didn't sound entirely happy about it, "But he isn't actually a member of the NYPD."

Castle nodded, "That I'm not."

"He's out mascot," Ryan joked.

They all laughed aloud, while Castle looked a little hurt, although he was soon laughing along with them.

"Make the call Beckett," Gates instructed as she headed back towards her office.

The four of them all headed back to their desks to make the call. Beckett and Castle took their seats while Esposito and Ryan pulled their chairs from their desks to sit with them, so they'd all be able to hear the phone call.

"I'm not going to be able to put it on speaker phone," Beckett stated, "Because chances are he'll know it and won't answer, if he even answers at all."

The three men all nodded their understanding and moved their chairs closer, in the hope that once Beckett made a connection they'd be able to hear at least a little of the conversation.

Beckett looked to Castle for a moment and he nodded, he was ready for this, because if the phone was answered then the person on the other end was his father, a man who had a lot of explaining to do.

Beckett looked at her phone then placed the piece of paper that she had written the number on beside it. She picked up the handset and placed it to her ear before she began to dial. She pressed the numbers slowly, making sure that each number was punched in correctly. When Beckett had input all the numbers she waited patiently for the call to connect.

"It's ringing," she muttered after a moment.

Castle let out a low sigh, it if was ringing that meant the number was still connected and hopefully meant that it was still in use, which would hopefully mean that someone was going to pick up on the other end.

"Still ringing," Beckett muttered.

"Come on, come on," Castle mumbled impatiently.

Beckett gave him a smile and rested a hand on his where it was lying on the table, telling him to calm down without words. Castle stopped mumbling but his leg began tapping impatiently.

Ryan and Esposito looked at each other then back to Beckett; they wanted this case over but didn't want answer as much as Beckett and Castle seemed to.

Their attention all snapped to Beckett as she spoke. "Ah John Smith I presume, or would you prefer I call you Jackson Hunt?"

With those words they all knew the call had been picked up and someone had greeted Beckett on the other end.

"Well Mr Hunt, I'm sure you recognise my voice, after all it would seem that you seem to know a lot about the direction my investigation has taken, after all you did send your man in here to steal all our files and information," Beckett said softly into the phone.

Everyone remained deathly silent as Beckett listened to what was being said on the other end of the line. "We're not going to meet you Hunt, not after the last time."

Castle leant in closer and heard the reply. "My dear Detective, you don't have much of a choice if you want your answers, we either meet or I disappear once again and you'll never hear from me again."

"Disappear the same way you did after your night with Martha Rogers all those years ago?" Beckett asked, "The night that your son was conceived."

Ryan and Esposito shared a look of sudden understanding, now they knew why Castle and Beckett had wanted answers so much, this man was Castle's absent father. They both looked to Castle, wondering how he was taking all of this, but all they saw was the man staring at Beckett intently.

"My you have been done a lot of digging," they all heard over the phone, "And are you sure that you still don't want to meet Detective."

Castle quickly scribbled something on the piece of paper with the number on it and moved it so that Beckett could read it. "We'll meet Hunt, but on our terms, we pick the time and we pick the place, no hoods over the head this time."

"You can't expect me to walk into a police precinct Detective," Hunt disagreed.

"I was thinking somewhere a little more public actually," Beckett explained, "That way we can be assured of everyone sticking to the plan."

"I'm all ears," came the faint reply.