Marcus Hale appears for the first time in Ch.2 "Neon Rain" without prior introduction
Zara Okafor appears for the first time in Ch.3 "The Spire Ascent" without prior introduction
The Archivist appears for the first time in Ch.5 "The Archivist's Offer" without prior introduction
Tomas Reyes appears for the first time in Ch.6 "Memory Wipe" without prior introduction