EPISODE CONTEXT

Sitting at episode 50 of 113, this filler episode arrives directly after 'The Future Planet,' a warmer, more hopeful chapter, making the tonal pivot into dread feel deliberately jarring. 'Ghost Tunnel' doesn't advance the central journey toward the end of the line, but it stress-tests Tetsurou's resolve in isolation — a recurring device the series uses to deepen his character between major arcs. It bridges into the two-part 'Artemis of the Transparent Sea' story ahead, making this a brief but atmospheric pause before the narrative picks up momentum again.