Contact Other Plane
You mentally contact a demigod, the spirit of a long-dead sage, or some other knowledgeable entity from another plane. Contacting this otherworldly intelligence can break your mind. When you cast this spell, make a DC 15 Intelligence saving throw. On a successful save, you can ask the entity up to five questions. You must ask your questions before the spell ends. The DM answers each question with one word, such as "yes," "no," "maybe," "never," "irrelevant," or "unclear" (if the entity doesn't know the answer to the question). If a one-word answer would be misleading, the DM might instead offer a short phrase as an answer. On a failed save, you take 6d6 Psychic damage and have the Incapacitated condition until you finish a Long Rest. A Greater Restoration spell cast on you ends this effect.
Contact Other Plane 5e 2024 vs. 2014 edition differences
The 2024 version allows casting as a ritual; the 2014 version does not. The 2024 version states "break your mind" instead of "strain or even break your mind." On a failed save, the 2024 version imposes Incapacitated until a long rest, whereas the 2014 version causes insanity until a long rest.