|First aired:||December 15, 2008|
|Previous spoiler:||Our Father|
|Next spoiler:||A Clear and Present Danger|
The heroes find themselves teaming up against one another and the good, or bad, in all of them comes to the surface - Robert Forster, George Takei, Brea Grant, Jessalyn Gilsig, Jamie Hector and Blake Shields guest star.
In the aftermath of the showdown against Arthur Petrelli, the Petrelli brothers (Adrian Pasdar and Milo Ventimiglia) find themselves battling against one another and Nathan makes a move that will have global repercussions. Meanwhile, Sylar (Zachary Quinto) holds Claire (Hayden Panettiere), H.R.G. (Jack Coleman), Meredith (guest star Jessalyn Gilsig) and Angela (Cristine Rose) hostage at Primatech and a face-off ensues. Elsewhere, Ando (James Kyson Lee), Matt (Greg Grunberg) and Daphne (guest star Brea Grant) continue their attempts rescue Hiro (Masi Oka) -- and Dr. Suresh (Sendhil Ramamurthy) may be their only hope. Ali Larter also stars. Ntare Mwine, David H. Lawrence XVII and Chad Faust also guest star.
- 12/14 -- Exclusive: Interview with David H. Lawrence XVII aka Eric Doyle
- 12/11 -- Title has Been Changed Again - The title is now "Dual"
- 12/11 -- Episode 3x13 - 2 Set Interviews and 1 BTS Clip
- 12/11 -- Episode 3x13 - 4 Sneak Peeks
- 12/10 -- Full Summary of Behind the Eclipse 10 Reveals several new details including Ando will get an ability in Episode 3x13 Duel
- 12/10 -- TV Guide reveals casting for Sylar's father
- 12/9 -- TV Guide reveals spoilers for Episode 3x13 - Duel & Volume 4 Fugitives
- 12/9 -- Episode 3x13 Sprint Sneak Peek ( Here's the same video but viable for non US viewers => Sneak Peek )
- 12/8 -- Episode 3x13 Duel - NBC Promo
- 12/8 -- Episode 3x13 Duel - What to Expect and Beyond
- 12/8 -- Episode 3x13 Duel Canadian Promo
- 12/2 -- Official Press Release has been changed to identify the episode as "Duel".
- 11/25 -- Official Promotional Pics Released
- 11/24 -- End of Volume 3 Revealed by Greg Grunberg
- 11/24 -- Official Press Release - Reveals that the episode's title has been changed to Duality.
- 11/20 -- Acording to IMDB, Monica will come back in this episode.
- 11/18 -- There will be a "devastating" showdown between the Heroes and Villians.
- 10/8 -- Echo De Mille will show up.
- 9/16 -- The title of this episode, "War", has been revealed.
- Sylar will take Eric Doyle's powers.
- Hiro will regain his ability by using the last batch of the original formula created by Dr. Zimmerman.
- Nathan will remain in charge of Pinehearst and he and Peter will be at odds through the next season.
- Angela will die in this episode at the hands of Sylar
- Matt Parkman will not be present in this showdown.
- Harry Fletcher will show up and kill Flint, showing his Ability.
- Nathan will survive and comeback to Haiti to be a warlord.
- Ando's powers will manifest at the beginning of this episode.
- Ando will have the red laser abilities shown at the beginning of the season.
- Peter will kill Nathan.
- Nathan will be inadvertently killed by protecting Peter from Sylar.
- More than one character will die in this episode.
- Meredith, Flint, Daphne, and Nathan will die.
- This episode will show the battle between good and evil according to the promos, and the looming battle between the Company (Angela's team) and the Pinehearst Company (Arthur's team).
- Echo will return to Primatech Research for revenge and face-off with Sylar's sound manipulation, destroying the facility in the process.
- The title refers to the ability of all humans to do good and/or evil. There is a hero and a villain in all of us, even Sylar, Peter and Arthur.
- Kaito's ability will be officially revealed in this episode.
- Kaito's power will be accelerated probability, that is how he has been so successful in life.
- Kaito's ability will be intuitive aptitude which is why he knew he needed to die from Adam.
- Daphne will be killed, setting Matt onto a darker path.
- It has been confirmed that both Daphne, and Matt are present in volume 4.
- Tracy will die.
- Many main and minor characters will be put in a terrible situation together -- like an explosion or a shootout -- which will be the cliffhanger for the end of the season, leaving us to figure out who lives and who dies.
- Monica and Micah will join Angela.
- Ando will return to Tokyo and use his new ability to overthrow Fumio Fukazawa.
- Nathan will take over Pinehearst after Arthur's death at the hands of Peter and Sylar.
- Knox is going to die.
- Hiro will use the younger Hiro to go back to the present time.
- Sylar will not kill Angela because she is his real mother with Linderman as his father.
- Peter will get only his Empathic Mimicry back, now that Arthur is dead, probably Hiro also. They may not know it, or it will be near the end of the episode.
- Peter will regain his abilities by a boost of the formula.
- Maybe Peter will regain all his abilities from an injection of the formula as his ability relies on altering his genetic structure to remember or recall different abilities which he has absorbed from people who he had an empathic relation with that came with in his proximity. Also in episode 3x12 Arthur did inform to Peter that " Son the formula is here we can get your abilities back, we can start over."
- Mohinder will inject himself, making the effects of the corrupted injection reversed.
- As always at the end of each season Peter will save the world, this time he will destroy the formula.
- In Peter's attempts to destroy the formula he needs to face-off with Nathan and Mohinder, however during the process realizing how weak he is without powers he will use the formula on himself to ensure he has the abitliy to save the world from potential arising threats and then destroy it.
- Peter may now hav the catalyst since he was the only one left in the room when Arthur died. However it may be that when one holds the catalyst he does not have the ability to regenerate because it was told that in order to kill one with cellular regeneration is to shoot them in the back of the head (previous seasons). So this may result to why Peter has the scar in the future or the one Arthur gives him.
- Sylar asks Eric Doyle if he thinks he can control him because Sylar is not affected by Doyle's ability.
- Claude saves hiro from falling and delivers him to kaito.
- Ando will go to Pinehearst with Daphne and Matt to inject himself with Hiro's former ability, but he receives something else.
- Ando, Daphne or Matt will convince Peter to save Hiro, once Peter regains his abilities.
- Claude will save Hiro, having had returned to the rooftop after Noah received Claire and witnessed Arthur's ambush. Arthur was the other mimic Claude referred to in The Fix.
- Hiro doesn't get saved and shows up late in show aged 16 years and now has a dark side to him from living in hiding for so long and training with his sword. Fights Peter which results in Peter's scar.
- Sylar will kill Meredith then Eric Doyle will take revenge but he wont be able to control Sylar.
- Eric Doyle will die at the hands of Sylar
- Ando recieves the ablity of empathic mimicry.
- Knox and Flint will team up with Peter, to take his brother down, after he fired them.
- The title of this episode will never stay consistent.
- It will literally change mid-episode.
- Eric Thompson will star by giving a syringe which contains the formula to Noah Bennet, Noah then will gain the ability of Telescopic Vision.
- Possibly Noah will go after Howard Grigsby first in order to train with his new ability.
- Eric Doyle will protect Meredith against Sylar.
- Hiro is one of the 1st synthetic humans.
- Since Sylar lost most of his abilities to the Shanti virus last season, and regained a number of new abilities this season, a similar situation will occur to Peter. DNA never changes, so Peter will regain his empathic mimicry with a boost of the formula, and get a number of new abilities yet to be shown.
- Mohinder will attempt to cure himself with a fresh injection of the formula, but it only accelerates his mutation and he quickly becomes his future self.
- Tracy is actually Barbara, having kidnapped and replaced Tracy during her Parris Island trip.
- Peter will have 2 injections, the first one will give him mental manipulation, the second will give him Empathic mimicry
- A certain puppet master will be the main villain for volume 4.
- Meredith will die, and she will make Doyle swear that he will protect Claire.