Investigation Held by ZnaToKi / Season 1 Season guide Investigation Held by ZnaToKi: Season 1 23 episodes Premiered Feb 14, 1971 Updated Jul 23, 2026 Spoiler-safe Advertisement Season 1 Episodes Episode Guide 🛡️ SPOILER SHIELD Season 1 Progress Shield All Safe I'm Watching Caught Up Season: Season 1 Last Watched: None (Not started) Episode 1 Episode 2 Episode 3 Episode 4 Episode 5 Episode 6 Episode 7 Episode 8 Episode 9 Episode 10 Episode 11 Episode 12 Episode 13 Episode 14 Episode 15 Episode 16 Episode 17 Episode 18 Episode 19 Episode 20 Episode 21 Episode 22 Episode 100 Future titles & synopses blurred. Tap "Reveal" on any card to peek. Binge Efficiency Engine Season 1: Filler vs. Essential Canon Filter episodes by narrative weight. Focus on essential mytharc and skip standalone side quests. 9% 91% Mytharc (2): Crucial lore & season climaxes Core (21): Character development & subplots Side Quest (0): Standalone / filler Show All (23) Crucial Mytharc (2) Essential Canon (23) S1·E1 Mytharc Episode 1 Feb 14, 1971 · 55 min S1·E2 Core Episode 2 Apr 18, 1971 · 55 min S1·E3 Core Episode 3 Nov 9, 1971 · 55 min S1·E4 Core Episode 4 Feb 8, 1972 · 55 min S1·E5 Core Episode 5 May 29, 1972 · 55 min S1·E6 Core Episode 6 Sep 16, 1972 · 55 min S1·E7 Core Episode 7 Nov 11, 1972 · 55 min S1·E8 Core Episode 8 Sep 1, 1973 · 55 min S1·E9 Core Episode 9 Nov 10, 1973 · 55 min S1·E10 Core Episode 10 Aug 26, 1975 · 55 min S1·E11 Core Episode 11 Jun 4, 1977 · 55 min S1·E12 Core Episode 12 May 20, 1978 · 55 min S1·E13 Core Episode 13 Nov 11, 1978 · 55 min S1·E14 Core Episode 14 Oct 19, 1979 · 55 min S1·E15 Core Episode 15 Nov 9, 1980 · 55 min S1·E16 Core Episode 16 Nov 14, 1981 · 55 min S1·E17 Core Episode 17 Nov 9, 1984 · 55 min S1·E18 Core Episode 18 Mar 23, 1985 · 55 min S1·E19 Core Episode 19 Dec 27, 1985 · 55 min S1·E20 Core Episode 20 Apr 11, 1987 · 55 min S1·E21 Core Episode 21 May 21, 1988 · 55 min S1·E22 Core Episode 22 Nov 11, 1989 · 55 min S1·E100 Mytharc Episode 100