You call upon the connection with the Plane of Shadow to summon a 10x10 feet large gate with the anchor hovering over the gate which appears as vortex of shadowy blackness through which nothing can be seen inside a plane filled with dim light or darkness. When you cast the spell you decide which of version you summon from these options:

Gate to Shadows. As an Action any object or creature can pass throught the portal and instantly arrive at (or around) desired destination in the Plane of Shadows. This gate allows both way movement. If casted in the Plane of Shadow, the other gate will appear at the anchor location in the Material Plane. If the location or the anchor in Material Plane is obstructed the spell fails. If there is no anchor in the Material Plane, the spell also fails.

Gate Through Shadows. When you choose this version, you may select another place which is in dim light or darkness within the range of 300 feet that you can see. A mirror gate opens in the same spot. As an action any object or creature can pass through the portal and instantly arrive at the destination. The gate works only one way.

Both version of the spell lasts for 1 minute or until you stop concentrating on the spell. Additionally you may decide to leave the Anchor of the gate at the summoned location (for further use as described in the "Gate to Shadows" option). It is going to be stay levitating in the location. The anchor can be forcefully removed if a creature succeeds at DC Athletics check. The DC is your spell casting DC.

AN: The spell is supposed to be difficult way for a DK to teleport in material plane (basically requiring 2 actions to port anywhere) with added difficulty to find a non-bright light area. Additionally it can serve to transport one-self to the Realm of Shadow with added difficulty that if you take the anchor with you, you cannot return to Material Plane and if you do leave it somewhere it needs to be well hidden or one risks it being taken away.