“The 3XK killer is back, or is he?”  This is the first line of the episode, and a little sneak preview into what we can expect from the episode.  Will Castle and Beckett finally be able to bring the 3XK killer in for justice?

***** SPOILERS BELOW *****

The episode starts with my favorite kind of scene, a cute one between Castle and Beckett.  Beckett remarks about how well Castle raised Alexis, and how she’ll be there for the beginning “next time.”  She and Castle then get into a baby discussion, where Castle says there’s never a right or a wrong time.  Mid-discussion, Beckett gets called off to her newest murder victim, Susan Watts (Laura Coover).  Watts was an ex-drug addict, whose ex-roommate says she moved out a few months ago when she got some mysterious, well-paying job.

Esposito and Ryan can’t find anything on the new job or any tax withholdings, so they figure it must have been illegal or paid in cash.  Ryan does find reference to a job placement agency that she may have gone through to find the job, so they start there.  Lanie figures out quickly that there is something fishy about this, and remembers their case with the victim Pam Hodges, where the victim had a backstory similar to Watts.  She thinks the two cases are connected.  When Lanie gets the x-rays back she calls Beckett to tell her that she believes the same doctor performed plastic surgery on Watts and Hodges.  If that’s the case, then Kelly Nieman (Annie Wiersching) and possibly the 3XK killer, Jerry Tyson (Michael Mosley), are back in town, despite never having confirmed that 3XK survived the fall off the bridge.

Beckett realizes this is more than a gut feeling for Lanie when she sees Nieman’s picture on the wall of the job placement agency.  Gates asks what they can do to make sure Nieman doesn’t escape again, and Beckett convinces her to let Castle assist on the case.  Gates emphasizes that he’ll be helping with this case only.  Ryan finds out that Nieman has been back in town performing plastic surgery for the last six months.  I’m just like why is this chick not on some watch or wanted list??  Anyways, Beckett goes to meet Nieman at the hospital she’s been working at.  Nieman denies knowing Watts or performing plastic surgery on her.  They find video footage from a street camera by the hospital that shows a woman who looks like Watts coming out with a gift bag from Nieman’s office.  She is seen getting into a vehicle, driven by none other than the 3XK killer.  He’s back!

Beckett and Castle interrogate Nieman, but she won’t crack.  All she gives them is the look-alike’s name, Amy Barrett (Laura Coover).  They go the address of a Michael Boudreau that owns the car from the camera footage, and there they find 3XK.  It all seems a little too easy at this point, so I’m sure there’s some sort of weird twist coming.

In interrogation, 3XK acts like he has never met Beckett or Castle.  He claims to be Michael Boudreau, and says he got cosmetic surgery to look like Jerry Tyson.  He says his surgeon was Kelly Nieman, so things are getting fishier.  Gates says the fingerprints of the man in interrogation are of a Michael Boudreau. Castle says 3XK killed Boudreau, and had Nieman graft Boudreau’s fingerprints onto his fingers.  But how can they prove it?  Gates says they only have a limited amount of time before they have to release him.  Beckett says finding the real Boudreau might be easier than proving this man is Tyson.

Castle speaks to 3XK and reiterates how this has to all be about 3XK’s mother; the man stares at Castle and it seems like he may be on to something.  Castle and Beckett find 3XK’s mother, but it turns out she isn’t his real mother; she just dated his biological father.  They manage to find a baby tooth at the mother’s house, and they hope to match the DNA to the man in jail.  Back at the precinct, Nieman is there waiting to pick up the man they have in custody.

Beckett runs into Amy Barrett and tries warning her she could be in danger, but she isn’t listening.  Later though, Amy calls Beckett to tell her she just heard about Susan Watts’ murder on the news and that she saw Watts and“Boudreau” together a few days ago.  Beckett goes to pick up Amy who says she’s scared.  Meanwhile, at the station, 3XK is being released.  On the street corner where she was supposed to pickup Amy, Beckett gets injected by someone and is taken off in a wheelchair.

Will Castle make it to Beckett in time?  What did you think of the episode?  Comment below!

Castle airs on Mondays at 10/9c on ABC. Watch full episodes on ABC.Go.com, Hulu and Amazon Instant Video.