The Ring Gate

The ring gates come from the structure the protomolecule builds on Venus, which travels beyond the orbit of Uranus and becomes a large ring-shaped wormhole. It leads to the Slow Zone, the hub of a network of 1,300 gates to other systems. Some ships passing through the gates disappear, and Laconia later shuts down travel through them. At the end of the series Holden destroys the Ring Station, cutting off the dark gods from the human universe and causing the gates to collapse.