There's a pool of blood in an alley, but no body. A white van was spotted fleeing the scene 20 minutes after a pair of gunshots rang out. An imprint matching a pricey briefcase is found in the blood. Lanie determines the victim is a male. Captain Gates is not impressed when Castle points out that this effectively eliminates about four million NYC ladies. Hey, it's better than nothing, right? Wrong. Castle and Beckett need a body.
The team finds the mystery van. It was used to transport the body to a cryonics facility. A special watch worn by the victim, Lester Hamilton, alerted the company that one of their clients had died. The cryonics lab CEO, Dr. Ari Weiss (guest star William Atherton) says the victim developed techniques for life extension. Hamilton's contract legally stops the cops from doing an autopsy. Once again, Castle and Beckett have no body.
Lester Hamilton's wife, Cynthia, says her husband truly believed in life extension. She shared Lester's sentiment that one lifetime together wouldn't be enough for them. These two were truly in love. Lester's colleague, Dr. Philip Boyd, explains that his friend was working on something called the Ambrosia Project. It involved pharmaceutical implants that would cause the body to produce young cells instead of aging ones.
Speaking of youth, Alexis learns she did not get into Stanford. She feels like a failure. Castle believes he may have overprotected his daughter to the point where she can't handle rejection. He explains to Alexis why he keeps his first rejection letter in a frame. It's what motivates him. Everyone gets rejected. How you handle it is what matters. Castle's such good dad. As far as the case...
Beau Randolph is a slimy porn purveyor of the "College Girls Gone Crazy" video series. He also happens to be the man who was funding Lester Hamilton's project. He wasn't happy when he learned Lester wanted to speed up the process of his research by publishing it online. Randolph knew that would destroy his chances of profiting billions from a patent. Sounds like a pretty good motive for murder, right?
Randolph has a large caliber gun that was recently fired, but there's no way to tie him to the shooting if they can't get the bullets out of the victim's body. Ari Weiss agrees to release the body, as long as they can continue to preserve Lester Hamilton's head. That'll work. Unfortunately, ballistics shows the bullets that killed Lester did not come from the porn king's gun.
Ryan and Esposito discover that one of Lester Hamilton's students broke into his office to change his grade. The kid's no killer, but his story leads the team to a seedy hotel where illegal human testing may have taken place. In truth, Hamilton was the having a procedure done on himself. Lanie needs the guy's head to determine why. Too bad the cranium in question has gone missing from the cryonics lab. Talk about losing your head!
Security video shows Lester's pal, Philip Boyd, breaking into the lab. Beckett and Castle chase the guy onto a fire escape where he accidentally drops the head into a dumpster. Castle dives in to retrieve the runaway noggin. Boyd says he was giving illegal treatment to his friend to treat his brain tumor, but his experimental procedures didn't work. Boyd didn't kill his friend. He was trying to save him.
Lester Hamilton's brain was deteriorating due to the tumor, but he wanted to keep working on his research. His wife, however, wanted to preserve his brain before it was ravaged by the cancer so that they could be together in the future. The police find her hubby's briefcase in her building. She gave it to him as a gift and couldn't just leave it there after she shot him in a crime of love.
Dr. Ari Weiss is alerted that a client has just flatlined. The signal from a special watch is coming from inside the precinct. Castle and Beckett rush to Cynthia Hamilton's holding cell. They're too late. Cynthia swallowed a cyanide pill she had hidden in her ring. Her lifeless hand holds a picture of herself and Lester close to her heart.
Castle wonders if they'll truly reunite in the future. Beckett believes it's possible. She says, "That's what the great love stories are about, right? Beating the odds." Castle and Beckett both hope they'll make it. They're speaking, of course, about Lester and Cynthia.