1. The Flash Season 1 Episode 8 (Flash vs. Arrow)
  2. Arrow Season 3 Episode 8 (The Brave and the Bold)
  3. Supergirl Season 2 Episode 1 (The Adventures of Supergirl)
  4. Supergirl Season 2 Episode 2 (The Last Children of Krypton)
  5. The Flash Season 3 Episode 8 (Invasion! Part 1)
  6. Arrow Season 5 Episode 8 (Invasion! Part 2)
  7. DC’s Legends of Tomorrow Season 2 Episode 8 (Invasion! Part 3)
  8. Supergirl Season 3 Episode 8 (Crisis on Earth-X Part 1)
  9. Arrow Season 6 Episode 8 (Crisis on Earth-X Part 2)
  10. The Flash Season 4 Episode 8 (Crisis on Earth-X Part 3)
  11. DC’s Legends of Tomorrow Season 3 Episode 8 (Crisis on Earth-X Part 4)
  12. Supergirl Season 4 Episode 8 (Bunker Hill)

Approximately 9 hours in total