Shawn gets a visit from a woman named Zola, a contortionist from a show called Le Cirque, needing help locating the star member of their troupe, Francois. Shawn agrees to meet her at their fairgrounds later that day to get a psychic reading on the place.
Minutes later, after Zola has left the Psych Office, we learn Rachael, Gus's new girlfriend, has left her son Maximus with Gus for the day. Gus and Max haven't quite hit it off yet, so Gus has been desperately trying to find an activity that would impress him. Shawn suggests they take Maximus to Le Cirque. This excites Max and Gus heartily agrees; however, Shawn leaves out the fact that he's attending Le Cirque because of a lead on a possible case.
When Shawn, Gus and Maximus arrive at a dress rehearsal for Le Cirque, Gus starts to worry because he specifically told Rachael he was taking Maximus to an actual performance, not a dress rehearsal. He doesn't want to upset her or Maximus. Just as Shawn is telling Gus everything will be okay, Shawn notices a man named Jeffrey Duke, the owner of a successful portable bathroom chain, setting up shop near the performance tent. He tells Gus that Duke is a ruthless wise guy and the "Gotti of Potties." After Shawn makes a few more observations about their surroundings, Gus figures it out that Shawn is at Le Cirque on a case, and Gus and Maximus are stuck there with him. Gus starts to worry even more. Just then, Gus realizes he's forgotten about keeping an eye on Maximus and sees that Maximus has indeed gone missing. Shawn and Gus freak out and start frantically searching for where he ran off to. Seconds later, Gus gets a call from Rachael checking in. Gus tries to cover up the fact that Maximus is missing, and just before he has to come clean to her, Shawn and Gus find Maximus and everything is okay.
Meanwhile, Lassiter's girlfriend Marlowe has gotten out of jail and has been set up with a hard-nosed parole officer named Ursula whom Lassiter had drunken relations with at a past police mixer, but never called back the next day. Ursula, still feeling the sting of rejection from Lassiter and now armed with the knowledge that Lassiter and Marlowe are involved romantically, tells Lassiter and Marlowe that under the guidelines of her parole, Marlowe has to live within a strict perimeter that barely leaves out Lassiter's house. The normal relationship they've been longing months for isn't going to happen right away as they had hoped.
During the Le Cirque performance, Shawn is surprised to hear that Francois is performing in the show; Francois was the man Zola needed help finding. Shawn tells Gus that there is no longer a case to be solved and Gus is relieved; they can now just sit back and watch the rehearsal without having to worry about a case. Just then, Francois' body is launched high into the air during the trapeze portion of the show, but the second he is about to touch hands with his trapeze partner Hugo, Francois's limbs go limp. He plummets to the ground and dies. Gus immediately covers Maximus' eyes, shielding him from seeing a dead man lying on the ground. Gus takes Maximus home from Le Cirque and is then tasked with having to come clean with Rachael about what Maximus saw. Rachael is furious with Gus, but Gus tries to explain that is was a mistake why they were there and that he wants to make it up to Maximus by taking him out for another big boy makeup date. Rachael says no to this idea and leaves the room upset. She doesn't know if she can trust Maximus with Gus again, and that worries her.
Later that day, Lassiter tells Juliet about the less than desirable situation regarding Marlowe's parole. Juliet feels bad for them and suggests that Marlowe stay with her and Shawn until she is no longer on parole.
Shawn and Gus head back to Le Cirque to offer their condolences to Zola regarding Francois' untimely death. Zola is beside herself; she doesn't understand how Francois could have missed that catch, considering he's done it a thousand times over. Shawn agrees that there is something fishy about that. He tells Zola that he and Gus want to help find out what really happened to Francois, but in order to do so they need to be performers in the show for maximum investigation access. Zola grants them their wish and Shawn and Gus find themselves dressed as circus performers being told they have to go on stage for a show that night.
While on lunch break, Shawn spots Hugo, the performer who was supposed to catch Francois on the trapeze but didn't. Shawn and Gus head over to question Hugo. Hugo tells them that Francois was supposed to extend his arms but he didn't, and therefore it wasn't Hugo's fault he fell. Shawn and Gus agree that Hugo is innocent.
From there, Shawn and Gus meet Juliet at the coroner's lab to get the autopsy report on Francois. Woody tells them that Francois was dead before he was launched into the air during the trapeze act. Francois didn't die from a broken neck in the fall; he died from electrocution. Based on this evidence, Juliet decides to open up a murder investigation on the death of Francois.
Later, Rachael gives Gus a second chance with Maximus and lets him pick him up from soccer practice. Maximus tells Shawn and Gus that while he wandered off at Le Cirque, he accidentally stumbled backstage and saw two fellow performers (disguised in stage make-up) applying make-up on Francois. From this information, Shawn believes that whoever Max saw was the person or persons who had a hand in killing Francois. Shawn asks Maximus to help identify the men he saw. This immediately alarms Gus; he knows he cannot mess up with Rachael again. But Shawn convinces Gus anyway and all three head back to Le Cirque to identify the potential suspects.
At Le Cirque, Max hears a familiar voice -- a voice belonging to the guy applying make-up to Francois. Shawn sees that this guy is talking secretly to two other performers. Shawn thanks Maximus for his help. Shawn's next move is to follow the three performers to get more information. Gus objects, knowing that they would have to bring Maximus along. But Shawn doesn't listen to Gus and all three of them head out to follow the three suspects.
Back at Juliet and Shawn's house, Juliet tells Lassiter that she's slightly uncomfortable with Lassiter always being over and engaging in lovey-dovey behavior with Marlowe. After all, she and Lassiter are co-workers, and there should be some boundaries. Lassiter apologizes to Juliet, but can't help but defend himself. Ursula has made it nearly impossible for him to spend time with Marlowe and it's frustrating him beyond belief. Lassiter knows this living situation is only going to get worse, so he assures Juliet that he will think of a different solution.
Shawn Gus and Maximus follow the three performers to a fortified lab - a lab they see the performers break into. Shawn sees a sign on one of the gates that says, "Danger! Electrified Fence." From this, Shawn believes these performers are thieves and that Francois was one of them. And during a robbery one night, Francois died from electric shock from the fence and his partners in crime had no choice but to cover up his death. Shawn tells Gus that they need to get in there immediately to follow them. Gus says he will not endanger Maximus again. But while this whole argument has been going on, Maximus has already escaped from the car and Shawn and Gus see him running after the thieves in question.
Meanwhile back at Juliet and Shawn's house, Lassiter and Marlowe announce their new plan for how to beat Ursula's tough parole restrictions. Lassiter and Marlow want to live together and the only legal way they can do that is to get engaged. So they did.
Back at the lab, Shawn and Gus immediately chase after Maximus. They follow him inside the lab, but before Shawn can get any leads, the alarm has been triggered and the cops show up moments later.
Shawn, Gus and Maximus are taken into the SBPD for questioning. Rachael gets wind of this and is appalled by Gus's lack of responsibility with her child. Gus feels like this is all Shawn's fault; Gus would have never taken Maximus on a case had Shawn told him that's what was going on in the first place. Rachael decides it is best that she and Gus break up. Right after Gus tells Shawn the news about Rachael breaking up with him, Lassiter announces to the entire SBPD that he and Marlowe just got engaged. This stings Gus, and Gus lets Shawn have it; he's tired of always getting in trouble because of Shawn's impulsivity and lack of responsibility. He really likes Rachael and now she's gone. Gus tells Shawn that he needs time alone and leaves.
Juliet tells Shawn that the performers stole an expensive substance from the lab called "tritium" that is used to make watch faces and exit signs. The street value of just 10 grams of it is worth $300,000. From this, Shawn makes the connection that the performers were also behind the sign factory robbery that Juliet had been investigating simultaneously. Juliet then wonders where they would store such a fragile, dangerous substance that needs to be handled very carefully. From this, Shawn flashes back to a few observations he made at the Le Cirque tent that point to a location where the performers may be storing the tritium.
Shawn follows the lead he just discovered to a storage warehouse. He keeps calling Gus, telling him to get there because he found the suspects' vehicles parked outside, but Gus' phone keeps going to voicemail. Gus is purposely ignoring Shawn. Just then, Shawn sees the three performers handling the fragile canisters of tritium.
Shawn gets them to admit to stealing the tritium, but they swear that the stolen tritium is not for personal use; they were only stealing the tritium in exchange for U.S. Visas from a shady business dealer named Jeffrey Duke who has access to forged documents. But after they lost Francois, they told Duke they wanted out of the deal, so Duke ended up kidnapping Zola, saying he wouldn't release her until they delivered the last batch of tritium. Shawn wants to help, so he forges a plan to save Zola and take down Duke in the process.
At Duke's Warehouse, Shawn creates a diversion by dressing up as a man from the County Pest Control. He wears a large backpack with a hose attached making it look like he is there to spray the place with pesticides. But in fact, Shawn is wearing a large backpack because one of the performers is concealed in it. Shawn tells Duke and his men that he will be personally spraying each of Duke's potties. Shawn makes his way into one of them, and when inside, the performer concealed in Shawn's giant backpack emerges. The performer climbs out of the top of the potty and sets a plan in motion that will bring down Duke. Shawn then sprays Duke and his men in the face, allowing Zola to be able escape. Duke and his men are now distracted by the stinging in their eyes and have trouble seeing the scene play out in front of them.
Zola and the performers use their contortionist and acrobatic skills to escape Duke and his henchmen. Shawn takes cover in a port-o-potty and suddenly, Gus shows up. He had gotten Shawn's last message and wanted to be there to help. Shawn apologizes profusely for his mess-up regarding Rachael and Maximus. Gus forgives him and they prepare themselves to face Duke and his men. Duke and his men are still blinded by the substance Shawn sprayed at them and are therefore shooting their guns blind. Bullets are flying everywhere as Shawn, Gus and the performers try to make it out of the warehouse safely. Just then, the SBPD shows up and takes down Duke and his men.
In the end, Rachael forgives Gus for endangering Maximus. She tells him that Shawn called her and explained the whole ordeal and that it was Shawn's fault that Maximus was put in any sort of danger. She also tells Gus that Maximus has been more confident and outgoing during this past week and that she has Gus and Shawn to thank for it. She tells him that she wants to give their relationship a second chance - just as long as he keeps her son out of trouble in the future.