Beyond Wikia
Hollow Sky pin

The "Hollow Sky" logo

Hollow Sky is an organization of scientists specializing in research about human consciousness and accessing The Realm. It is run by Isaac Frost and organized by Tess Shoemacher.

To an outsider, they appear to be a charity and support group (exempt from paying taxes) that gives hope to those people who have lost loved ones. However, their work is more sinister - and their main goal is to contact the afterlife.

Frost claims his main objective to be allowing everyone to have a chance to see their loved ones again, but in actuality, he has a personal objective - to bring back Celeste.