Was it all a dream? That's what Castle's wondering as wakes up in bed. Alone! Fear not, Caskett lovers. Our favorite mystery man and his muse are, indeed, together at last. A smile crosses Castle's face as Beckett walks into the bedroom wearing a loose white dress shirt and nothing else. Gulp.
Castle isn't quite ready to announce his new lady love to his family when Martha and Alexis come home unexpectedly. Beckett sneaks out the front door while Alexis recovers from her first hangover. Apparently graduation festivities got a tad out of hand. Too bad they showed. Castle was in the process of removing that white shirt from Beckett's body button by button before they were so rudely interrupted. Gulp again.
Back at the station, Ryan lets Captain Gates know that Beckett's shooter, Cole Maddox, swiped a photo from Roy Montgomery's wedding album. Castle reveals it's the person who has been keeping Beckett safe all these years. They do what they do best to identify this mystery man as Michael Smith, who has been tortured by Cole Maddox. He's still alive, but the incriminating evidence file he was keeping has gone up in flames.
Castle and Beckett check out a piece of property Smith owns. Another file may be hidden there. It would be in a place safe from the demolition crew that has been working there. The backup file is hidden in a floor safe in Smith's office. Castle and Beckett would love to search it. If only Cole Maddox hadn't arrived to get the drop on them. He ties them up and locks them in a bathroom. Not good.
Castle and Beckett try desperately to free themselves before Maddox returns. They'd both feel totally ripped off if they were murdered now. At least they had last night, right? In other news, a suspended Esposito has been working the case from afar. His fancy detective work leads him to the office building where he frees Castle and Beckett. Of course, Espo's wondering what Castle is talking about when he says to Beckett that they should've done this four years ago.
The team finds Maddox just as he opens a booby-trapped floor safe containing the NYPD file. BOOM! An explosion blows the file into a million pieces. Maddox, too. Later, Ryan shows up at Beckett's place with the all scraps of file he could gather from the crime scene. He and Esposito put aside their differences long enough to piece together the file. They find bank documentation for an illegal payoff. The account belongs to a powerful U.S. Senator named William Bracken. This is the man responsible for Beckett's mom's murder.
Michael Smith pulls through surgery. He tells Castle and Beckett that Bracken is powerful and untouchable. This becomes evident when Smith ends up dead in his hospital bed. They'll be coming after Beckett next. Castle wants to take her away, but Beckett knows she'll never be safe. That's why she sneaks away while Castle is sleeping to crash a political fundraiser. She's going to confront Senator Bracken. Castle fears she'll do more than that. He thinks she's going to kill him.
Beckett bluffs her way into the fundraiser. She slips a phone into Bracken's jacket pocket. RING! Beckett calls the senator to arrange a private meeting. Castle and Esposito convince Ryan to delay a call to Gates until they track down Beckett, who is holding Bracken at gunpoint in a closed kitchen area. She wants him to admit to the murders he's been behind. Bracken tries to justify his actions. This doesn't fly with Beckett. Unfortunately, she knows Bracken has too much power. So, she bluffs.
Beckett says she has another copy of the file. She rattles off the number of Bracken's illegal bank account. She promises to not go public with the information as long as she and everyone she cares about remain safe. Beckett assures Bracken that she's done being afraid. It's his turn now. WHACK! Beckett bashes her gun to the side of the senator's face. The scar that will be left should serve as a solid reminder that she's out there.
Beckett lets the team know that she'll get justice for her mom. It just won't be today. For now, she'll be content with getting justice for others. She convinces Gates to let her back on the job. She'll still have to serve out the rest of her suspension. That's cool. Beckett assures Castle that she'll figure some way to pass the time as she reaches for something other than the elevator button just as the doors close. One more time... Gulp!