Yugo and Rin are happily reunited. However, Rin suddenly tells him to duel her and shoves Yugo out of the tower. Meanwhile Kaito is thrown out of Ruri's tower in the same manner, and is rescued by Kurosaki and Edo. Kurosaki runs to his sister when he hears she attacked Kaito, and Edo explains about the Doctor able to control minds. Kaito goes to see to Kurosaki while Edo runs to tell Yugo. Yugo crash lands on his D-Wheel and worries for it, and Rin confronts him, not caring if it is. Yugo reminds her about their work building the D-Wheel together, but Rin is unmoved and demands a duel. Yugo accepts, deciding to duel her to reach her heart.
Rin takes the first turn and activates "Wind-Calling Bell Chime" and reveals "Wind Witch - Ice Bell" in her hand to summon a copy of it from the deck. She then normal summons the one in her hand and activates their effects, each inflicting 500 damage to Yugo. Since she controls at least two Wind Witch monsters, Rin special summons "Wind Witch - Snow Bell" from her hand and performs a synchro summon, summoning "Wind Witch - Winter Bell." Winter Bell's effect lets it copy the effect of a Level 4 or lower Wind Witch in the Graveyard; Rin chooses Ice Bell and deals another 500 damage. She sets a card and ends her turn. Rin tells Yugo they'll duel in a way he's familiar and leaps on her monster to fly off, turning it into a Turbo Duel. From her Academia duel disk and behavior, Yugo wonders if Academia did something to Rin and resolves to find out.
Yugo Synchro Summons "Clear Wing Synchro Dragon," but Rin activates her trap "Bewildering Wind," negating Clear Wing's effect and halving its ATK. Yugo sets a card and ends his turn. Watching the duel, the Doctor laughs at his control of Rin and looks to Leo for approval, but Leo warns him to not let Rin get injured as the girls are critical to the Arc Area Project. Rin draws "Parasite Fusioner" and attacks Clear Wing with Winter Bell. Yuya banishes "Speedroid - Three-Eyed Dice" from his Graveyard to negate the attack, but Rin activates the Quickplay spell "Call of the Wind Witch" to special summon a monster from her hand with a lower level than a Wind Witch she controls. She summons Parasite Fusioner and activates its effect, letting her perform a fusion summon since it was special summoned.
Rin fuses Fusioner and Winter Bell to summon "Wind Witch - Crystal Bell." Fusioner's effect then equips itself to Crystal Bell, allowing Rin to destroy Fusioner in place of Crystal Bell should it ever be destroyed. Crystal Bell destroys Clear Wing, and the force knocks Yugo off the tower, smashing his D-Wheel. Rin descends and demands the duel continue. Yugo tries to reach out to her, reminding her of the hopes and dreams they pinned on that D-Wheel. Rin coldly uses the effect of Crystal Bell to copy the effect of Ice Bell in her Graveyard. Yugo is down to 450 Life Points and the force shatters his helmet visor. Rin tells Yugo to give up, but he refuses after he found her after so long. Yugo takes his duel disk from his D-Wheel and throws off his helmet to continue the duel.
Yugo summons "Speedroid Red-Eyed Dice" and activates "Step on Shadow," letting him revive Clear Wing. He tunes Clear Wind and Red-Eyed Dice to summon "Crystal Wing Synchro Dragon." Crystal Wing attacks Crystal Bell, the effect of Crystal Ring increasing its ATK by Crystal Bell's ATK. Rin uses the effect of Crystal Bell to copy the effect of Clear Wing in the Graveyard to destroy Crystal Wing, but Yuya uses the effect of Crystal Wing to negate the effect and destroy Crystal Bell, destroying Parasite Fusioner instead. Yugo's attack lands and Crystal Bell is destroyed. Rin falls to 1000 Life Points. The force throws her back and Yugo runs to her. Rin opens her eyes and whispers his name, and Yugo embraces her.
Suddenly, Rin declares Crystal Bell's effect, letting her revive Parasite Fusioner and Winter Bell. Rin pushes Yugo away and stands up as her monsters return. Since Parasite Fusioner was special summoned, its effect activates again, and Rin fusion summons another Crystal Bell. Crystal Bell copies the effect of Ice Bell and deals 500 damage. Yugo loses. The Doctor orders Rin to return to the Professor, leaving Yugo behind.
Meanwhile, Reiji explains to the other Lancers on his boat about his trip to Academia three years ago, and his request to Yusho to help stop Leo resulted in him crossing dimensions himself. Reiji also tells Yuya about a term he saw in Leo's research, "Revival Zero," that involves Yuri and Serena, but he otherwise has no idea what it means. However, this confirms to Reiji that the dimensional counterparts of Yuya and Yuzu are somehow the key to uniting the four dimensions. Later the Lancers arrive on the island.
This episode contains the following tropes:
- All for Nothing: The Doctor (through Rin) wants Yugo to suffer with one thought in his head: everything he did in an attempt to save Rin was all for nothing.
- The Bus Came Back: Kurosaki and Edo arrived in the nick of time to save Kaito after he was pushed off by Ruri.
- Clothing Damage: Yugo's helmet visor gets damaged during his Duel against Rin.
- Cycle of Hurting: Destroying Crystal Bell just sets up a combo that lets Rin instantly summon another one.
- Even Evil Has Standards: Leo is not all that impressed by the Doctor's control of the bracelet girls, brushing off his fishing for approval and telling him to make sure they aren't harmed by what he's done, as they need the girls for the Arc Area Project.
- Hope Spot: For a second it looked like Rin was back to normal after Yugo destroyed her monster. Then she revives it and promptly finishes him off.
- Jerk with a Heart of Gold: Reiji's past interactions with Yusho makes it clear that he's not as selfish and cruel as his father.
- Meaningful Name: The titular "Threatening Toll" is actually Rin, who's already been infected by the Doctor's Parasite Fusioner by the time Yugo finds her.
- Mythology Gag: This isn't the first time a Riding Duelist got the visor in his helmet damaged while Dueling a mind-corrupted Love Interest.
- People Puppets: A combination of this and mind control. Thanks to his Parasite Fusioners, the Doctor able to turn Rin and Ruri into his mindless puppets and use them to dispose of their friends.
- The Promise: Reiji, it is about time you should tell Yuya about Yusho's sudden disappearance!
- Rule of Symbolism: The actual translation of this episode's title is "The Sound of the Bell that Bares Fangs". At the end of the previous episode, it appears that the spider (Rin) wants to "eat" the butterfly (Yugo) with her "mandibles".
- Slasher Smile: Both Ruri and Rin sports their own.
- Uriah Gambit: The Professor using Rin and Ruri as suicide bombers on the heroes is definitely a dick move. Although he still needs them for his Evil Plan.
- Used to Be a Sweet Kid: The picture of Yuri as a child seems to suggest this.
- Wham Episode:
- Two of the bracelet girls, Rin and Ruri, turn out to be the first two victims of the Doctor's Parasite Fusioners, and Yugo is in a very big trouble against the former.
- And then there's the Professor's other Evil Plan: Revival Zero.
- Wham Shot: A minor one, but Academia's documents containing pictures of Yuri and Serena's child selves may imply that the former was Used to Be a Sweet Kid.
- The Worf Effect: Rin gives Yugo a run for his money and beat him (this includes damaging his helmet and wrecking his D-Wheel) not only just to show how badass she is, but also demonstrate the terrifying power of the Doctor's brainjacking.Yugo: Rin! Did you forget all the feelings we put into this D-wheel!?