Descendants 3 “Under the Sea” Promo The third installment in the Descendants franchise premieres this Fall on Disney Channel. Show More… Comments Related Videos Black Lightning 1×08 Promo “Revelations” (HD) Season 1 Episode 8 Promo Black Lightning 1×07 Promo “Equinox: The Book of Fate” (HD) Season 1 Episode 7 Promo Black Lightning (The CW) “Critics” Promo HD Madam Secretary 3×03 Promo “South China Sea” (HD)