The Web of Shadows concerns the return of the heroic Toa to Metru Nui. There, they find an old enemy has overtaken the great city with the help of Visorak--robotic spiders that can quickly encase anything or anybody in near-indestructible webs. The Toa undergo a bizarre metamorphosis while sealed within strange cocoons, and emerge as clunky-looking machines made up of mismatched parts. Though horrified, they find that they also possess some new powers, which prove essential for their subsequent journey to restore Metru Nui--and themselves. This delightful Bionicle installment is probably easily accessible for any viewer unfamiliar with the series to date.
Bionicle 3: Web of Shadows
The Toa Metru return to Metru Nui to rescue the remaining sleeping Matoran, only to find it overrun by the spider-like Visorak horde and its ruthless, sadistic rulers, Sidorak and Roodaka.