Masaru and co. are making their way to Mercurimon’s palace at Infinite Ice Ridge when they come across a valley that has buildings lining its walls. The valley is preventing them from moving on so Masaru leads them in so they can get across. While looking around on top of a building, a Kuramon provides surveillance to Ikuto, Falcomon, and Gotsumon. Gotsumon tells Ikuto that they are doomed because no one goes into the valley and leaves unharmed.

The kid’s Digimon begins to sense a presence and a group of Dokgumon appear and entangle everyone in their webs, dragging them deeper into the valley. The Dokugumon hang the kids from a web and entrap their Digimon. The kids hear a Digimon in the distance who says their hearts will be theirs. The Digimon puts them to sleep and Agumon and co. try to wake them up to no avail. The Digimon finally appears and Gaomon tells us it is MetalPhantomon, the ruler of the valley. From the palace, Gotsumon and co. watches on and tells his companions that he puts to sleep intruders his minions offer and feasts upon their souls while showing them nightmares.

MetalPhantomon begins to drain their souls and their nightmares begin with the kid’s Digimon watching on helplessly. Masaru has a nightmare that a Drimogemon has taken Chika. He is trying to catch her but a Numemon gets in his way. Every time he kills one it reappears and multiplies. Yoshino has a nightmare of herself when she was a kid. Her younger self is crying and acting emo. MetalPhantomon tells Agumon and co. that they are remembering what hurts them the most and what they want to forget. Touma’s nightmare begins and he is back in his home town. He sees various scenes of him and his mother enjoying themselves together. He is briefly shown a scene of when she is dying in the hospital and then is brought to the day she died. He runs to his old house thinking that perhaps he can stop her from dying. In reality the Digimon continue to watch on and Gaomon says they must rely on the strength of their hearts.

Touma reaches his old house and sees a younger him and his mother exit the house-about to head off to a summer festival. He tries to grab hold of his mother and force her to stop but he just passes through her. He continues trying to stop her from going to the festival but she doesn’t hear him. They come to the end of the street where a truck loses control. Touma’s mother throws the younger Touma out of the way and hits her. The older Touma breaks down crying. MetalPhantomon believes he has won but Touma starts to remember all the good times he had with his mother. He breaks Metalphantomon’s spell and we see Touma telling his mother he will always remember her in his heart. The webbing restricting Touma dissolves and he awakens with his digisoul engulfing his body. He uses perfect evolution to digivolve Gaomon into MachGaogamon. MachGaogamon frees the other Digimon and Masaru and Yoshino.

The Dokugumon try to restrict the kids again but they’re able to evade them this time around. Raramon and Agumon digivolve and fight the Dokugumon while MachGaogamon handles MetalPhantomon. MetalPhantomon throws buildings at MachGaogamon but he evades them. MetalPhantomon uses an attack called Soul Predator that destroys his own minions but MachGaogamon flies right through it and destroys him.

The kids and their Digimon are now out of the canyon and Touma says they need to push on. However, when Yoshino tries to get up she faints.