You call upon ancient power, seeking their guidance and knowledge. Until the spell ends, you gain the ability to cast any spell from the warlock spell list of 5th level or lower without expending a spell slot or needing to prepare the spell. As part of casting this spell, you can cast a spell with a casting time of an action from your newfound spell list. However, the cost of using this power is steep. At the end of each of your turns, you must succeed on a DC 18 Intelligence saving throw or take 2d10 psychic damage. If you fail this saving throw two times, the spell ends early and you gain a short-term madness.   At Higher Levels. When you cast this spell using a spell slot of 9th level, it no longer requires concentration, though you can choose to end the spell whenever.