The everful horn of a vengeful bull-like creature who wants it back…
It is a magical bug, that will allow the owner to hear what is said in the immediate vicinity of the “bug.”
This tome may give you the information you seek, though you may not be happy reading it. Not really cursed, but gives the information in such a way that many readers despaired before finding the right knowledge.
Some parallel worlds have different time-flows, like the fabled dwelling-places of the elves: those who visit them under the hill for a night return to find that years have passed in this world. Perhaps it is the gate leading between the worlds which causes the alteration. If a gate were 'misaligned', the shift from '| |' to '| \' or '| /' as it were would lead to that difference, much as a light-beam split and bent by a prism ends up taking a longer path. There might even be a mathematical function linking degree of misalignment to alteration of time-rate.