Deep undergroud dwells an immaterial spirit being that can appear to the brave adventurers who are resourceful and brave enough to find their way to the oracle.
Those who are worthy to meet the oracle can seek answers to any question they have regarding the past, the present or even the future. The oracle spirit answers by speaking incomprihensible riddles or by showing glowing images of strange events, symbols and writings.
What one will make out of the oracle's answer is up to themselves, but often the oracle's messages prove eventually useful. Directly or indirectly.