For you to have a near-death experience, Death must have a near-YOU experience. Take care to treat him well, and you may be rewarded... eventually.
The PCs are accosted in a major city containing at least one famous fortuneteller / prophet of the future. They are informed that their as-yet-unborn child will (insert terrible evil), and that, although they are very sorry, the PC must be executed to keep this from happening.
A terrible teleportation incident makes inter-demihuman chimaera of all the PCs. Quoth Master Adams: 'I teleported home one night / with Ron and Sid and Meg / Ron stole Meg's heart away / and I got Sidney's leg.'
Telepathically linked twins that have the ability to switch places. Literally. They've learned to exploit this 'tag-team' throughly.
What if some crazy wizard created an artifact that empowered rodents that touched it with one random supernatural power? Preferly right out of the pages of your favorite four-color. (But only one power!) This item does not convey any sort of intelligence boost.
Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.
The old pantheon is dead, starved to death from lack of worship. If a powerful mortal can create a cycle of Faith, he can become a New God, to some limiting point.
Somehow, someway, a band of gnomes learns how to be ninjas. In fine gnomish style, they open an academy to teach this art to other gnomes. Wacky Hijinks ensue. Or the gnomes become some of the finest assassins in the land. Or both.
THE GNOMES OF UDNALOR: Part II
Having left the hush of the upper halls, and crossed the depths of the Braeth (an underground river, which is not all that deep because bear in mind we're talking about gnomes here), you would find yourself in Wattling Street, the main road through Udnalor. It's actually a long, well-worn passageway which opens out eventually into the City Centre. The gnome-buildings branch off Wattling Street as small burrows or caverns with boulder-blocked doorways for privacy. You can find armourers and smiths (though their armour tends to be on the small side for humans to buy) and many other types of trader.
There are many streets, ginnels and cooies which run off Wattling Street, the most famous probably being Smell Street, the domain of the infamous gnomish alchemists, the eponymous smell being very distinctive: the stench of cooking fungus, the aroma of subterranean spices, the pungent reek of rotting carcasses (used in some of the more notorious experiments). An encounter with an alchemist can really be spiced up (excuse the pun) if you have a well-stocked herb cupboard, and actually make up the potions, elixirs and draughts as they are ordered by characters.