A woman creeps out of her room with a pizza box in her hand. The garbage upstairs is full, so she tries to shove it down the garbage shoot. Suddenly, a body drops from a floor above onto her level, then, continues its way down. The woman screams.
In Castle's apartment, he's playing with a toy helicopter, irritating Martha. Alexis enters and says she is volunteering for the NYPD for three days. Beckett calls, they've found a body.
Lanie and Beckett stand around the body which has been shot once to the chest at close range. The victim is Sam Parker, who's registered address is in Connecticut. Esposito reveals that the victim was shot on the 15th floor 15 and the woman who found it is a hottie.
Back at the base, they find that Sam had a wife and two kids and did not have an apartment where he was found. Beckett and Castle head to the morgue for the wife to ID the body. There is already a woman there, and Beckett sets about comforting her, when the door opens and another woman comes in, stating she is his wife. Beckett asks the other lady who she is, and she says she is the fiancé.
They put the women in two separate rooms where they glaring at each other. Captain, Beckett and Castle explain the whole wife/fiancée thing. They interview the fiancée first, who says she knew the victim as Jake Holland. They met a work and had been together for 6 months. She said she didn't know it was all fake. Turns out Jake/Sam would spend the week in the city with fiancée, Sarah, and weekend with wife, Mrs. Helen Parker. The wife is outraged and denies that he would do this to her. She says he started working in the city at a recycling plant 6 months ago, because he was passed over for a promotion at his old job, another recycling plant. She says she didn't know that he was having an affair.
No sign of struggle at the apartment but they find Jake Holland's wallet. They also find an iPhone, with a not-so-friendly message on it. It says "I'm not going to let you get away with it, you worthless piece of trash. If you don't call me back tonight, then my next call is to Heaven". The message is from the victim's wife's brother.
Beckett and Castle interview the brother and fin out Sam owed him $20, 000 and he never paid any of it back. The brother's alibi checks out. They also find out that the Parker's are broke. They go to see Parker's his new boss. He says that he got glowing recommendations for a man who didn't exist. And he thought that Sarah and Jake were "a pretty solid couple".
None of the numbers that Jake gave his boss are still working.
The fiancée turns up and says she saw Mrs. Parker parked outside Jake's apartment so Beckett and Castle go to talk with the wife. She denies being outside the apartment and implicates the fiancée.
Esposito says the company, Connecticut Solutions, that Sam worked for is going broke. Sam joined their rival, New York Recycle. New York Recycle came up with new technology. Ryan finds that all of the fake phones were billed and registered to Connecticut Solutions and it looks like Sam was a corporate spy.
New York Recycle doesn't believe that Sam was a spy but perhaps Sam was after the new battery recycling formula, and Sarah was on the team that researched it. The cops grab Sarah and Jake's computers.
Jake was sending emails to his old boss about chemicals able to recycle batteries. Beckett and Castle interview Sam's boss, Andy, at Connecticut Solutions. He admits to planting Sam there, offering him a million dollar pay day to steal the formula. He also admits Sam called him the night he was murdered to say he finally had the formula. But Andy had been told that before, he'd spent loads on research, all coming blank, so Andy fired him. Then he called, saying he found something, so Andy drove up, saw the cops and went back home. Beckett says that Andy shot him because he couldn't pay him 1 million dollars.
Esposito and Ryan tell Beckett that they have Helen Parker for assault and Sarah for trespassing. Ryan wants pictures. Sarah says that Helen tried to rip her handbag off her shoulder and she only went back for her pen.
Beckett thinks they're missing something since it's a long way to go for a pen. Then she remembers that Sarah said Sam had an ulcer, but according to Lanie, he had a clean bill of health. So where was he going the last three Tuesdays when his fiancée thought he was at the doctors?
The first week he was at an address on an island, the second at New York Recycles processing plant, then the third at a port.
Ryan and Esposito tell Beckett and Castle that Sam was asking about shipping at the processing plant and port, and that the address belongs to a Lauren Branston. The photo is of the fiancée. She faked a name too.
They interview the fiancée. She denies it, until they pull out the driver's license and social security number. Also, it appears that Sarah/Lauren has worked for a lot of other companies, all under new identities. Beckett summarizes that the new boss suspected Sam/Jake was a spy and told her to 'intercept' him. She admits it, saying 'she was only doing her job'. She was supposed to look like she had fied information, so Sam/Jake would bite. All she had to do was leave her laptop around his apartment, with an incomplete chemical formula on it. Then they tell her that Sam knew she was a fake. She doesn't believe it, but the evidence is undeniable. Beckett implies that Sarah knew Sam knew, and killed him. But Sarah has an alibi - she was at her daughter's recital.
Her alibi checks out. They realize that if the entire relationship was fake, then why did Sarah give Sam her grandfather's pen? What was she really looking for in Sam's office? Beckett and Castle check it out and find whatever Sarah was looking for she had shredded. So they had to piece it together.
The shredded stuff was pictures that Sam took on his phone. It reveals that New York Recycle wasn't recycling batteries, just changing labels and dumping it in the sea. The only one now with a motive is Andy. They find his gun in the dumpster and it's a perfect match.
They tell the wife the good news. Sam wasn't unfaithful, he was trying to help the world.