By drawing a circle of black chalk up to 15 feet in diameter and chanting for one minute during the casting time, you open a portal directly into the Plane of Shadow. 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 at the destination. The portal remains open for 1 minute or until you stop concentrating on the spell, and it can be used to travel between the Plane of Shadow and the chalk circle, in both directions, as many times as desired during the spell’s duration.