The journey had been a long one and now they had entered the mountains. After an entire day spent on paths cut into the mountainside and through moss covered coniferous woods, they encounter a desperate young mountain tribal. He is searching for his beloved wife and his elder brother, both of whom he got separated from after an unsuccessful attempt to kill a cave bear. The last thing he saw was the cave bear in full pursuit of his wife. He could not help her as he had been knocked to the ground by the raging beast, and was struggling to regain full consciousness. The tribal will be clearly nervous and urges them to look for his wife during their travels. He will stay in his village a couple of miles to the north and pleads for assistance should they recover his wife, whether she be dead or alive.
On the next day of travel, they will journey upon a dim track in the forest and while they are preparing to ascend another path cut into the mountainside, they hear moans of lust from somewhere nearby. Upon closer inspection they will spy a young tribal woman in the heat of the act with an elder tribal male. They are consummating their forbidden love on the cold mountain moss, and beside them lay the skinned and slaughtered carcass of a huge bear.
A PC Conjurer or summoner, basically any mage whose sole purpose in life is summoning creatures to aid in battles and various situations, is cursed with a hex, and needs to find a way to undo the curse...before he goes mad, or his fellow PCs throw him out of the party, or worse.
Everything he/she summons, never goes away. So you'll have to figure out what the heck to do with that dire bear or fire elemental once it's done fighting the orcs for you. Eventually a caravan of bizarre creatures either annoyingly ends up following the summoner around, or they go off to cause mayhem elsewhere. Bad news for the poor spell-caster regardless.