Shadow Realm Gateway

By drawing a circle of black chalk up to 15 feet in diameter and chanting for one minute, you open a portal directly into the Shadow Realm. The portal fills the chalk circle and appears as a vortex of inky blackness; nothing can be seen through it. Any object or creature that passes through the portal instantly arrives safely in the Shadow Realm. The portal remains open for one minute or until you lose concentration on it, and it can be used to travel between the Shadow Realm and the chalk circle, in both directions, as many times as desired during the spell's duration. This spell can only be cast as a ritual.