Plot

Driven by his nightmares, Reid stays behind in Las Vegas to find his father in order to find out the truth about Riley Jenkins' murder.

Based on his nightmares, Reid decides to stay in Las Vegas to probe deeper into his nightmare, specifically if his father, William Reid, who abandoned him and his mother when he was a child, was the murderer of six-year old Riley Jenkins when Reid himself was only four. Rossi and Morgan decide to stay and assist Reid. Reid learns that his father has been living just outside of Las Vegas all these years. Upon meeting his father, Reid confronts him with his suspicions. Reid Sr. denies any involvement or knowledge of the murder. Immediately after Reid confronts his father, an anonymous source provides another suspect for the murder. After going into hypnotherapy, Reid also thinks that his mother, Diana, is suppressing some memories from an incident surrounding the murder. Diana decides to go off her medication so that she can remember what happened the night that caused her mental instability. Meanwhile, J.J. goes into labor, three weeks before her due date.—Huggo

The last time we saw Spencer Reid, he was dreaming of a small dead boy in a basement ... with his father standing over the body. Now we see the young doctor explaining to his colleagues that he plans on staying in Las Vegas in order to visit his mother. Rossi, Derek and J.J. look skeptical -- and a bit suspicious.

Sure enough, Reid enters the local police station. "I'd like to see everything you have on a 1984 murder of a boy named Riley Jenkins," he says. The man who worked the case, Detective Hyde, explains that it went cold long ago. "The family got defensive and stopped cooperating," he says. Reid, who isn't telling the whole truth and nothing but the truth, says FBI interest in the case has to do with "research."

Later that night, Reid returns to his hotel room to find Derek and Rossi waiting. The two have stayed behind to help their young friend. "Riley Jenkins?" Derek asks. "I know what this has been doing to you." He then asks Reid to describe the suspect. "Truth is I don't know anything about him," Reid says. "He's my father."

Rossi and Derek are shocked at first, but seem to have recovered by the end of the opening credits. Reid, meanwhile, wastes no time in sharing what he has learned. The boy was picked up on his way home from little league practice, sexually assaulted, stabbed nine times with a knife and then stuffed behind a dryer. The unsub, Reid theorizes, would now be a white male in his 50s -- just like dear old dad. Says Rossi: "The man were looking for is a pedophile, so I'll ask you again: Are you sure you want to go down this road?"

Indeed he does. Reid and Derek pay a visit to Riley's father, Lou Jenkins, and ask about William Reid. The man doesn't want to cooperate -- acts downright hostile, actually -- but warms when Reid reveals who he is. Lou Jenkins says Reid's father is "a good man" who still works as an attorney in town. "He was 10 minutes away and never let me know," Reid says. Turns out Spencer hasn't seen his father in 20 years.

Reid, Derek and Rossi show up at the law firm, where papa Reid is shocked but happy to see his son. Reid, on the other hand, is clearly angry. "You remember Riley Jenkins?" he asks. "I saw his killer and it was you." Dad gets mad mighty quickly and -- being a big-shot lawyer and all -- says the team can't search his personal files without a warrant.

So, on his way back to the hotel, Reid calls Garcia with a request: Hack into dad's files anyway. Garcia is reluctant but Reid insists. He then notices a manila envelope underneath his hotel room door. An attached note reads: "You're looking at the wrong guy." Inside the envelope is an old police file on Gary Michaels, a convicted child molester. Rossi and Derek agree the timing suspicious, but insist on checking out the new suspect.

Garcia calls. "Let me tell you what I didn't find," she says. "No kiddie porn, no dubious emails, no chat-room history." Papa Reid's financial files are also clean. "From what we can tell, Reid, he doesn't fit the profile," Hotch says. The team thinks Reid will be encouraged by the news -- but the spurned son remains convinced that his dad is guilty of murder. So convinced, in fact, that he pays a visit to Dr. Jan Mohikian, a hypnotherapist. "We won't be using this for evidentiary purposes," Reid says. "It's really just for me. The suppressed memories are about my father." The session begins and we see flashes of memory: Reid's parents arguing ... his mother sobbing ... his father burning bloody clothes.

Reid confronts his mother, who claims not to remember anything. She begins sobbing, then screaming. A nurse enters and gives Diana a sedative. "It could have been you," mom whispers. "It could have been you."

Back at the police station, Reid wants to bring in his father for questioning. Detective Hyde is hesitant, telling Reid to "go back to the Fountain View, have a drink and think about it." Garcia then calls to say that Gary Michaels went "off the grid" soon after Riley Jenkins was murdered. "Maybe he didn't want to stick around for the investigation," Derek theorizes.

J.J., meanwhile, is having labor pains. The team drops what it is doing and rushes her to the hospital. "Agent Todd, I hope you're ready because your job starts right now," Emily says to J.J.'s replacement. Todd appears just a wee bit intimidated.

Back inside the Vegas hotel room, something is bothering Reid -- and it's not excessive gambling losses. Who slipped the Gary Michaels file under Reid's door? Is someone trying to lead the team in another direction -- away from William? Reid is also disturbed by Hyde's comments. "He told me to go back to the Fountain View," Reid says. "I never told him we were staying at the Fountain View." Rossi looks at Derek -- the kid has a point.

Hyde, in the meantime, has fulfilled his reluctant promise and brought William in for questioning. "I didn't do this, Spencer," William says. "You're angry that I left. And you're right to be." Reid says his father can make it up to him by telling the truth. "I didn't kill that boy, but I know who did," William says. It was Gary Michaels, but William assures Reid that he doesn't "want to go down this road."

Garcia calls. Gary Michaels didn't disappear -- he died. Parts of his body were found buried across state lines some seven years ago. Someone beat the man to death -- probably with a bat. "Maybe it wasn't Riley's blood on those clothes your dad was burning," Derek says.

Rossi, Derek and Reid head to the county where Michaels' body was discovered. The local sheriff explains that a fingerprint was found on the victim's glasses, but didnt initially yield anything. Reid wants to compare the fingerprint to those of his father. "You're just determined to nail him, aren't you?" Derek asks. "It doesn't even matter what for." Reid only scowls.

Some time later -- about the time it takes to run a print, in fact -- Derek gets another call. William Reid's prints don't match those found on Gary Michaels' glasses, but prints belonging to Lou Jenkins do.

Derek and Reid head out to arrest Jenkins. Hyde, who clearly knew who the killer was the entire time (and slipped the file to Reid), asks to be the one to arrest his "friend." Under questioning, Jenkins reveals that he killed Michaels after a parent in the neighborhood informed him that the molester had approached another boy. That second boy? None other than Spencer. It all comes rushing back to our young braniac in FLASHBACK form. But who was the anonymous parent/ tipster? At that moment, Diana enters the interrogation room ... and confesses to telling Lou Jenkins that Gary Michaels had come on a little too strong to little Spencer.

In a FLASHBACK, we see Diana pointing Michaels out to Lou, who grabs a bat and enters the molester's house. A short time later, Diana follows. She finds Lou standing over Michaels's dead body ... and gets blood on her clothes in the process. Back in the present, William admits to burning those duds. "I knew that nobody could ever know," he says. "She could have been implicated. And I had to protect her." The tragic events also led to end of Diana and William's marriage. Essentially, the whole incident is why William left his family.

"I was wrong about everything," says a teary Reid. "I'm sorry!" William sits down next to his son. "I am too, Spencer," he says.

Days later, the team gathers around J.J.s hospital bed where the proud mother holds her newborn child. And wouldn't you know it? She would like Reid to be the godfather. Touched, Reid holds little Henry. "If anything happens to us, it's up to you and Garcia to make sure he gets into Yale," J.J. says.