Heather and Sierra

This article focuses on the interactions between Heather and Sierra.

Overview
With Sierra being one of the two new potential targets for alliances at the start of Total Drama World Tour, Heather decides to go after her from the start, seeing that her other new potential target, Alejandro, was so phony and fake that he obviously had another more sinister motive. However, having seen the first two seasons multiple times and knowing of Heather's infamy and deception on the show, Sierra is fully aware of what Heather can pull and decides to manipulate Heather's manipulations to her own advantage. Ultimately, they end up together on Team Amazon. Both go through periods of liking and hating one another with one trying to manipulate the other for their own motives, going from complete friendship to utter disrespect for one another. Heather admires Sierra's knowledge of the show but sees her as utterly insane, while Sierra sees Heather as a fellow female friend but knows of her evil and manipulative manner. Ultimately, by the end of the season, Heather and Sierra do gain respect for one another, particularly after Sierra becomes eliminated and loses her hair in the process, and when Sierra supported Heather after her beloved Cody is eliminated at the hands of Alejandro.

Celebrity Manhunt's Total Drama Action Reunion Special
When Sierra says that she knows everything about everyone, including their dental records, Heather calls her a stalker.

Walk Like An Egyptian - Part 1
Heather tries to form an alliance with Sierra to counter Alejandro's possible alliance with Lindsay. Heather pretends to like Sierra, but is actually very annoyed by her. In the confessional, Heather says "I do NOT heart the new girl." While the two go through the pyramid, Sierra sets off a trap that sends a row of arrows toward Heather's head, Heather is visibly angry, but she is able to control herself and pretends to forgive Sierra. Heather joins Sierra in a group hug with Cody, although she seemed reluctant to do it. Sierra seems to be unaware that Heather dislikes her, which appears to be quite odd, since Sierra supposedly knows everything about the contestants and should know of Heather's manipulative nature.

Walk Like An Egyptian - Part 2
Heather quickly agrees to switch Izzy for Sierra, possibly to further the alliance Heather wants with Sierra. She started to regret this when they didn't manage putter the camel inside their canoe. But in the end, with the help of Alejandro and Izzy, the camel finally got inside of it and Team Amazon won the challenge.

Broadway, Baby!
Heather reaffirms her need to manipulate Sierra (and Cody as a consequence) in order to survive on a team with Gwen and Courtney when they publicly acknowledge that they want to eliminate her next. When Sierra wanted to hug Heather, she (albeit purposely) rejected. However, Sierra states that she knows that Heather is playing her, so she's playing Heather back by pretending to be played. Later, when Team Amazon is receiving their rewards, Heather tells Sierra to not talk to Chris so that he'll forget how creepy she is, however, Heather quickly corrects herself by calling her "special" instead.

Slap Slap Revolution
Heather was seen sitting with Sierra in the winner's class cabin. Sierra was telling Heather about how she has become the president of her fifteenth Total Drama fan club. Heather wasn't very interested in this and changed subjects, asking if Sierra has any idea of who will be eliminated next. Sierra confirms and states that Team Chris Is Really Really Really Really Hot is the next to lose, due to overconfidence. Right after this, Sierra appears in the confessional and tells that every time Heather thinks she is using her, she makes a little notch on her belt. She took it off from her pants, showing her underwear and seven notches in her belt. This may have confirmed that in previous episodes, Sierra was truly aware of Heather's tactics, but didn't show it. During the sausage stuffing challenge, Heather points out that it is Sierra who is making them lose due to making a statue of Cody out of their meat instead of her when accused by Courtney of not helping out.

The Am-AH-Zon Race
When Heather found out that the Zing-Zings were just teenage Peruvian actors, Sierra comments that Heather isn't the goddess she thinks she is. Sierra decides to join Gwen and Courtney in voting Heather out, but in return, made Gwen promise that she wouldn't be as nice to Cody. She, along with her other teammates, was shocked when Chris revealed it was a fake elimination ceremony.

Jamaica Me Sweat
Heather calls Sierra "fanzilla" when she ends up splashing all the members of Team Amazon with her dive.

Sweden Sour
While trying to get Alejandro's attention away from Courtney, Heather claimed that she got some gum on the back of her butt. However, Sierra ruins it as she points to Heather that she doesn't have any gum on her. Later, when Heather was trying to hit Cody with a metal hammer, Sierra was then chasing her with a metal rod.

Rapa Phooey!
As Sierra vents about how she misses Cody due to Alejandro choosing him for his partner in first-class, Heather rants on and on in confessional about how Sierra's insane obsession with him is not helping anything. She does not say this to her face though, because she wants Sierra to remain her ally. Sierra was making fun of Heather and Alejandro and how they are obsessed with each other. Even though paired with her for most of the challenge, Sierra admits that alliances don't work and that she refuses to ally with anyone that isn't Cody. After "giving birth" to a second Cody in the form of a condor chick, Sierra becomes frustrated when it chooses Heather as his mother over her, even ruining her performance in the second part of the challenge due to losing frustration at Cody Jr. going after Heather mid-way up to the nest. By the end of the episode, Heather admits finally that Sierra is insane and can't be trusted in any true alliance.

Awwwwww, Drumheller
After Alejandro makes a fake digital photo of Cody and Heather sleeping together in the loser cabin, Sierra becomes angry at her throughout the challenge until Cody proves that it never happened. During the design-o-saur vote, Heather voted for Sierra due to her secret love of glitter glue and Sierra voted for Heather because the Chris dinosaur reminds her of her mom. Then later, Sierra squirts glitter glue in Heather's face out of her fury, to which Heather responds, "Real mature!". After finding out about the truth between Cody and Heather, Sierra agreed with Cody to vote out Alejandro and not Heather. When Heather was in the confessional, Sierra popped in and Heather jumped away and begged her not to murder her.

Planes, Trains, and Hot Air Mobiles
Sierra states that she can't let Heather win while at the firework stand.

Walk Like An Egyptian - Part 1
Heather chooses to ally with Sierra during their journey under the pyramid, working together to escape from the "mummy" chasing after them. Heather joins in cautiously in a group hug with her and Cody.

Super Happy Crazy Fun Time Japan
Heather stood up for Sierra, saying that the team should consider Sierra's opinion when Courtney was saying she should be team leader.

Slap Slap Revolution
Sierra told Heather about how she became the president of her blog.

Can't Help Falling in Louvre
Heather shows consideration for Sierra during her singing of Paris in the Springtime, yelling at Cody to take care of her and make sure she gets what she needs to get over her sorrow.

Sweden Sour
When Heather was singing at the beginning of We Built Gwen's Face, she seemed to be cautious that she was singing to Sierra.

Rapa Phooey!
After Alejandro chooses Cody for his flight partner in the previous episode, Sierra uses Heather as a psychiatric adviser to help try and figure out what is wrong with the two of them. Heather complains about Sierra in private, but chooses to try and help her in public. With Cody enchanted by Alejandro (and the reward of candy he won), the duo are forced to team up together, where they civilly help one another to the point of getting along, including running from the obstacles together and Sierra even made Heather a pouch to keep her eggs in. They both said that they disliked Alejandro and wanted him gone.

Awwwwww, Drumheller
Heather voted for Sierra's dinosaur as the best one created. Sierra also voted for Heather's dinosaur because she loved the idea that it was a Chris dinosaur and said she'll have to remember that idea. Also when Sierra accidentally blows up the plane, Heather appears to be concerned.

Planes, Trains, and Hot Air Mobiles
When Cody dug up Sierra from the rubble, Heather went and got her a wheelchair and a green feathered hat from Rapa Phooey! In the confessional, Heather says that she knows what it's like to be bald and that no girl, crazy or not, should have to be bald on television.

Hawaiian Punch
Sierra was seen cheering when Heather kicked Alejandro in the groin. In the alternate ending, she also looked concerned when Heather and Ezekiel fought over the million dollars.

Trivia

 * They were the final two females left competing in Total Drama World Tour.