The contestants must go through an extreme obstacle course with danger lurking around every corner. The rivalry between two villains emerges with a former antagonist speaking out the truth while a greater evil spreads a web of lies towards the rest of the cast. Meanwhile, someone attempts to clear her name regarding an embarrassment that hurt her relationship. In the end, a hero and his ally plot to defeat their current rival. However, this is not enough to prevent the flushing of a powerful manipulator, who gets his long waited comeuppance for what he previously did, but he manages to warn somebody about the threat before meeting his downfall.
On the girls's side of the loser cabin, Zoey and a distraught Courtney discuss the latter's new relationship ending because of Cameron kissing her. Zoey tries to lighten the mood by admiring Courtney for having accomplished this with not one, but two guys in one day, saying "she's on fire". This makes Courtney encourage herself, but, realizing the positions are now reversed in what started her conflict with Gwen, she asks Zoey not to say anything. Zoey happily agrees. It is then that Mike, with Mal still in complete control, gets her attention from the window. In the confessional, Mal describes leading Cameron to his downfall as being just like "scraping gum off his shoe; a bit sticky, but oh so satisfying".
Inside his mind, Mike and Chester meet up with Svetlana. Both males are confused at her building fish statutes out of butter, but she explains that either she follows Mal's orders, or ceases to exist. Mike asks her to join the resistance against him, as the scene cuts back to Mal's confessional. He reveals to the viewing audience that Alejandro is his next target, for foiling his plans to frame him in the previous episode. He tells her that Alejandro let Cameron fall down the mine, and Zoey, shocked, speculates that he rigged the votes against him two episodes ago as well. At this point, Chris calls all contestants to the beach. On her way down the cabin steps, Courtney comes across Scott eating dirt out of sadness. She yells at him that Cameron kissed her, and not the other way around, and that they are back together. Scott goes along with it, but says he is not willing to forgive or forget just yet, as "her kissing spree may not be over".
The contestants rush at Chris's threat to make the last one to arrive do fifty push-ups. Alejandro receives this task, and although he tries to argue back that he just returned from Boney Island, Alejandro brushes it off, for exposing Mal is his biggest priority, and not dealing with the sadistic host. He reveals that not only did he keep the DVD of incriminating Mal footage, he hid it somewhere in the McLean Spa Hotel for the right time. Chris explains the challenge as an "obsta-kill course" of booby-trapped tires, ropes made out of unusual material, "snapping bars", and a part called "Duck and Cover". For the second time in the season, Scott is overly confident, which pushes Chris to require the contestants to wear heavy packs throughout the entire thing. He adds that there will be a penalty for removing it at any time. Zoey talks with Gwen about Alejandro allowing her friend to fall, to which Gwen labels it as harsh for even his standards. Zoey proposes that they vote him off at the next elimination ceremony. Gwen agrees without hesitation. Courtney sees them, and becomes paranoid that they are forming an alliance, or gossiping about her kissing Cameron and Scott.
Alejandro strikes a conversation of his own with Mal, revealing he is fully aware of his evil nature, and that he is not who he pretends to be. Mal is unfazed, reasoning that no one will believe "the most manipulative contestant in Total Drama history". Alejandro then warns him about the DVD, to which the other crushes his hand, bringing the Spaniard to his knees. Alejandro takes his words back, and reassures him that his secret is safe, though he is obviously lying. Zoey approaches them, and Mal covers the situation by claiming he is helping a fallen Alejandro. In the confessional, Alejandro is determined to get the other contestants on his side. The contestants begin racing through the obstacle course, with Mal sticking by Zoey so he has a chance to enter the Spa Hotel, and search for the DVD should she win. Alejandro tries to tell Gwen of the danger, but is knocked out by a tire Mal throws.
When Mal and Zoey reach the ropes, she falls, being allergic to the dog hair, that hers is made of. He pushes her on, eating through the licorice which his rope is made of, to slow down the next person. Zoey tries another rope, with Gwen climbs the one she had just attempted. Zoey asks if she is allergic to dogs, which she confusedly replies she isn't. However Gwen understands once she learns of the dog hair, and laughs with the latter about how gross it is. Courtney and Scott arrive, and she shouts that Zoey better not be telling her about the kiss with Cameron. Gwen is extremely surprised. Scott adds fuel to the fire by mentioning that they were together at the time, which makes Gwen yell back that she wants to have a "little chat" with Courtney if they survive the challenge. While Courtney manages to finish climbing, Scott is unfortunate enough to be electrocuted by his rope, just as Alejandro goes to warn him about Mal. Alejandro decides to get back to Scott later, and proceeds on the licorice rope. It separates and falls to the ground, but he hangs on to the wall.
The next part is the "snapping bars", earning their name from the snapping turtles in the water below. Gwen sarcastically remarks that it's "hilarious", and Alejandro crosses the top of the bars on his hands before clinging to Mal. As Mal begins to strain himself, the scene shifts back to Mike's mind. He continues to urge Svetlana to join him and Chester, before she drops her carving tool and starts to fade. Mike worriedly asks what's going on. Screaming in pain, she responds that Mal is channeling her athletic abilities. Outside, Mal succeeds and becomes an evil version of the Russian gymnast, swinging and banging Alejandro against the bars. Zoey is confused, recalling that Mike previously was having trouble accessing his other personalities. However, she is ultimately relieved he did not transform into the "Mal character". Inside his subconscious, Mike begs Svetlana to fight back, and she acknowledges the chain encircling her foot. He smashes it with a nearby mallet, freeing her and pulling her from Mal's control. She exclaims that she will now help Mike and Chester defeat him. Without her, Mal falls into the water and is attacked by snapping turtles. He initially is taken aback by Svetlana's exit, but quickly realizes Mike is involved and punches the confession cam shattering it. Courtney and Scott come to the bars, and again, while she does well, he lags behind. She becomes frustrated and leaves him.
Zoey is the next person Alejandro tries to inform of the threat, but he is interrupted yet again, this time by Chef shooting them with a familiar gun. Laughing, Chris explains the meaning of the name "Duck and Cover" - contestants must duck and cover from leeches. Zoey runs on, as Courtney and Gwen arrive and hide behind a rock. Courtney explains that Cameron kissed her, to which Gwen questions why. Courtney replies that maybe it is because she's "pretty", and while Gwen agrees, she states that it came out of nowhere. The scene changes to Mal and Scott where Mal lies that it was Alejandro who made Cameron kiss Courtney instead of Mal himself, and Scott leaves to speak to Courtney. As he walks, his pack catches on a bush and he eventually ditches it, concluding that he will deal with the penalty when he wins. Gwen makes a fast retreat when he joins her and her friend. It is during the following chat that Courtney admits she also kissed Alejandro "years ago" while she and Scott weren't together. Mal approaches them asking for their loyalty in voting off Alejandro, and they say yes. Alejandro and Mal confront each other again, during which Mal plays a lethal card in calling him "Al".
The next part of the challenge is zip-lining to a finish line where Chris stands. Alejandro is ecstatic, having done this many times before, and screams Mal's name as he launches from the cliff. Zoey, who comes to realize that Alejandro is telling the truth, reasons that she must keep an eye on Mike after this. When he urges her to come with him, for the weight will make them faster, she compliments him by saying he "sounds like Cameron". As they come close to Alejandro, "Mike" jumps to Alejandro and hangs from his legs so that they both drop into the water below. Scott, Gwen, and Courtney are the last to reach this part of the challenge. With Scott lacking the necessary equipment, Chris laughs that this is the penalty he was talking about, and Scott is forced to proceed using only his hands. Courtney and Gwen start to zip, as Zoey crosses the finish line and wins immunity. The challenge is over, and only the girls have succeeded in finishing the course while the guys are each caught in tough situations.
At the elimination ceremony, Zoey, Gwen, Courtney, and Scott all keep their promises to vote off Alejandro, as well as Mal. Alejandro, on the other hand, not only votes for Mike, but creatively submits his selection by scribbling on his photo so he resembles a devil. Scott is highly amused and wishes he had thought of it. After Alejandro is voted off, Chris asks Zoey who she would like to join her in the Spa Hotel with Gwen and himself, but Gwen immediately cuts in that she cannot tolerate another night with him there. In response, Chris sends her on exile to Boney Island for the night, which Gwen is visibly not pleased by. Zoey invites Mike to stay with her, and they share a hug. Alejandro is flushed, but before his exit is complete, he proclaims that this game just got one hundred percent less beautiful, and that there is a greater villain at work and that "the truth is in the art". Zoey wonders what he means before Chris signs off.
After ending up at the Yukon, a snowmobile stops near Alejandro. To his surprise, it is Heather, who was also sent to the same location after her elimination. After Alejandro is slapped by Heather for causing her elimination, he tells her that he misses her. Heather smiles back and the two ride off on the snowmobile.
- Chef appears; however, he has no lines, though he is heard laughing during Chris's recap.
- Heather appears in an exclusive clip; however, she has no lines.
- This is the only episode in the season in which a female is exiled to Boney Island, and the only time one of the original twenty-two contestants is exiled.
- This is the first episode since his debut that Cameron is absent, although he appears in the recap and is mentioned several times throughout the episode.
- With Alejandro's elimination, Gwen is the only contestant left in the season who was previously a finalist.
- All of the females cross the finish line, while none of the males did.
- It is revealed in this episode that Alejandro and Courtney kissed at some point during Total Drama World Tour, though it is never shown onscreen.
- This is the last episode of the season where a contestant is exiled to Boney Island.
- Scott's sharp tongue once again causes Chris to increase the difficulty in a challenge, just as he did in Food Fright.
- This is the first episode since Evil Dread that Mike shifts to one of his four original personalities. In this case, Mal changed to Svetlana.
- Counting Alejandro's ending in Total Drama World Tour, this is the first time Alejandro has ever been eliminated. Thus, all contestants from the first generation cast have been eliminated at least once as of this episode.
- With Alejandro's elimination, this marks the first time since Chinese Fake-Out that there are more females in the competition than males.
- Scott and Courtney get back together in this episode after having broken up in the previous one.
- This is the second episode in which the editor humiliates Chris during the recap. The first time is during the recap of The Enchanted Franken-Forest.
- The drawing Alejandro did on Mike's picture was similar to the drawing Heather did on Eva's in No Pain, No Game, as well as what Geoff drew on the monitor of Alejandro himself in Hawaiian Style.
- Alejandro's line before his flush, "This show just got one hundred percent less beautiful", mirrors Justin's last words before his own elimination in The Princess Pride.
- The name of the episode is a pun on the term "Obstacle Course".
- Alejandro's last name, Burromuerto, is referred to as "Burrosmuertos" throughout the episode.
- Alejandro's bruise after his altercation with Mike are missing after his confessional, even immediately after Mike lets go of his wrist.
- When Chris explains the challenges, there are sixty tires on the ground; however, there are more when the contestants are running through them.
- Alejandro and Mike's backpacks seem to disappear and reappear in a few scenes.
- While climbing the rope, Alejandro appears to have five fingers on one of his hands for a few frames.
- Mal's multiple bites from the snapping turtles disappear by the next scene.
- Courtney says she kissed Alejandro years ago, even though Total Drama World Tour occurred only a little over a year prior to Total Drama All-Stars.
- Chris instructs all of the contestants to go to the beach for the challenge, but they meet him in the forest instead.
|Total Drama All-Stars episodes|
|Pre-merge||Heroes vs. Villains | Evil Dread | Saving Private Leechball | Food Fright | Moon Madness | No One Eggspects The Spanish Opposition | Suckers Punched|
|Post-merge||You Regatta Be Kidding Me | Zeek And Ye Shall Find | The Obsta-Kill Kourse | Sundae Muddy Sundae | The Bold and the Booty-ful | The Final Wreck-ening|