On the episode "Road Kill," Dexter never got a chance to use this kill room. He actually ended up saving Trinity's life instead.
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What is Trinity up to? He takes Dexter along for a road trip on the episode "Road Kill."
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Dexter Season 1 Quotes

I've lived in darkness a long time. Over the years, my eyes adjusted until the dark became my world and I could see. But then Rudy turned on the light. He flooded my memory and now I'm blind.

Dexter Morgan

There are no secrets in life, just hidden truths that lie beneath the surface.

Dexter Morgan