My understanding of the city of Colligo is as follows:
1. People arrive from other times and other dimensions.
2. Everyone arrives in the library.
3. There is no way to leave; attempting to do so means that that one is returned to the library.
4. People disappear without warning or reason.
5. The natives refuse to speak of the circumstances surrounding arrivals and departures, or about the force or being behind these kidnappings.
6. No one knows who or what is doing this.
7. There seems to be no purpose for being here.
8. The force behind all of this seems interested in our continued survival.
9. The city resembles late 20th-century, early 21st-century Earth. More precisely, a typical moderate-sized city in the United States of America. (This leads one to wonder-- why an Earth-style city? Why Earth-style technology?)
Please correct me if I have made errors.
( Starfleet Personnel )