Beseech Secret

Looking through the seeing stone, you enter a vision where you beseech your patron for arcane knowledge outside your power.

Choose a spell of 5th level or lower from the Wizard spell list.  Once during the duration, you can cast the spell you chose using one of your Warlock spell slots provided you have one available.  You can not cast the chosen spell as a ritual, even if it has the ritual tag.  Once you cast the spell this way, this spell ends.