WARNING! This article contains SPOILERS for Dexter: Original Sin season 1, episode 5!As Dexter: Original Sin season 1, episode 5 highlights Dexter and Deb’s sibling bond, the prequel reveals that a huge moment in the main series almost happened much earlier. When Dexter’s main series begins, it’s established that Deb is really the only person that Dexter unconditionally loves and deeply cares for, and vice versa for her. The two are presented as closer friends than the average sibling, which is further elevated by them being each other’s only family left and coworkers at Miami Metro. However, in Dexter: Original Sin season 1’s timeline, that tight relationship isn’t quite there yet.

https://screenrant.com/dexter-original-sin-deb-almost-discovers-truth-explainer/