- "Now when we built this place, we also made something that sorta acts like a compass-slash-map-slash-navigator..."
- —Harper to Jesse's Gang. src
- In the ending of "Access Denied", Harper mentions The Old Builders own the Atlas, which will help the gang find the way home.
- In "A Journey's End?", Otto presents the Portal Atlas to Jesse who then activates it in order to find the Overworld Portal, which leads Jesse's gang and Emily, (determinant), back home to the Overworld from The Portal Network.
The Portal Atlas appears to be a blue and yellow glowing book.
The Portal Atlas is a rare artifact that serves as a guide to the Portal Network and can be activated by simply saying where you want to go and opening it. Upon activation, it releases a torrent of ancient symbols which travel towards the holder's desired portal.
- Hadrian mentions to Jesse inside his palace that the "Atlas can see where people are from". This explains how Hadrian knew of Jesse's Treehouse and Axel and Olivia. However, it's power appears to be limited, as Hadrian failed to correctly discover the true identity of Reuben.
- Currently, the Portal Atlas is the only known way to navigate The Portal Network, with the exception of The Old Builders themselves.