In the desolate wastes of Antarctica, under thick layers of ice and snow, forgotten by the world and only remembered in a few databases of the ancients: There lies Psilabs; a major research complex into the human psyche and the powers of the human mind.
A treacherous door to enter. Take a deep breath, focus your mind, and leap into the ice.
"The wind-driven snow parts for the barest of seconds, revealing a glimpse of refuge from the deadly storm. It’s a massive sapphire pyramid. Yet you know of nothing like it in this area…"
In the trackless Frozen Waste, at the heart of the Sra lands lies the sacred glacier Ganamed, wherein lies Illyana’s Palace, the great ice necropolis of the Sra tribe.
With a huge number of sacrificial victims, another realm long ago secretly bound a Prince of the land spirits, Iorstonn by name, thus ensuring the fertility, and improving the magical defences, of their realm. But binding that Prince to one spot has disrupted the weather and magical patterns (ley lines?) over half the continent. Things have become bad enough that a coalition has been formed to rectify the situation, once divinations have established the cause.
Your party is one of the teams assembled to do the rectification: find the binding object and steal it ("so that we can destroy it here in our realm, of course"...*) or destroy it over there. Presumably the Prince will be grateful to his rescuers and angry at the binders, but with a greater spirit like Iorstonn one can never be sure: such beings are "tricksy".
* Of course, the rulers of our realm might want to control Iorstonn for their own ends...