The movie is a compilation of episodes 1-8 of the 2017 television series with new scenes added for the introduction. It covers the period from when Riko descends into the Abyss with her robot companion Reg, reaching the second layer where they meet the White Whistle Ozen who reveals information about Riko's mother. (Source: Wikipedia)

The movie is a compilation of episodes 9-13 of the 2017 television series. Riko and Reg descend to the third layer where Riko has her first experience of the Curse. They descend to the fourth layer where Riko's arm is injured by an Orbed Piercer and Reg tries to save her. Nanachi comes to their aid and saves Riko's poisoned arm. In return Nanachi asks Reg to kill her immortal companion Mitty. Nanachi then joins Riko and Reg in their quest to reach the bottom of the Abyss. (Source: Wikipedia)

Continuing their perilous descent down the Abyss, Riko, Regu, and newfound friend Nanachi reach the Abyss' fifth layer, The Sea of Corpses. Upon arriving at the research station known as Idofront, the main trio encounter the mysterious Prushka, the alleged daughter of Bondrewd, who leads them to the White Whistle responsible for Nanachi's dark past. Despite the welcoming appearances of Idofront's residents, Nanachi warns the young adventurers that things are not always what they seem. With the only route to the sixth layer shrouded in mystery and Bonedrewd's schemes awaiting them, what sacrifices must be made in order to continue the journey down to the bottom of the Abyss? [Written by MAL Rewrite]

In ancient Disboard, Riku is an angry, young warrior intent on saving humanity from the warring Exceed, the sixteen sentient species, fighting to establish the "One True God" amongst the Old Deus. In a lawless land, humanity's lack of magic and weak bodies have made them easy targets for the other Exceed, leaving the humans on the brink of extinction. One day, however, hope returns to humanity when Riku finds a powerful female Ex-machina, whom he names Schwi, in an abandoned elf city. Exiled from her Cluster because of her research into human emotions, Schwi is convinced that humanity has only survived due to the power of these feelings and is determined to understand the human heart. Forming an unlikely partnership in the midst of the overwhelming chaos, Riku and Schwi must now find the answers to their individual shortcomings in each other, and discover for themselves what it truly means to be human as they fight for their lives together against all odds. Each with a powerful new ally in tow, it is now up to them to prevent the extinction of the human race and establish peace throughout Disboard!

[Written by MAL Rewrite]