Ok, here’s what I got: a haunted water shrine in the Warrens of Tyr. A dwarven banshee, the shrine’s former cleric, haunts the site. Looking for ideas about what it should look like, what the banshee is doing, how the PCs will deal with the situation.

The Dwarven Banshee must be carrying on the focus of the dwarf cleric. I’m thinking he was excavating a tunnel to a cistern in Under Tyr. But I could use some inspiration.

How about this.
Down a dark and dead end alley way is a circular rusty grate in the street. If one spends enough time standing at the grate(why anyone would do this in the warrens is beyond me) you can hear water dripping. The shrine is under the grate and is a hollowed out room and your tunnel(trying to open up the cistern). The Dwarf found it, but in digging he unearthed something he should’nt have(what that is is up to you -something lovecraftian to some thing like an ancient artifact) that is causing current problems. Whether from people(maybe a PC friend or loved one) disappearing(either from what was unearthed or from the dwarf) to something more benign like tremors and colapsing buildings(from the digging). This draws the PCs attention somehow(if one’s a templar). The Dwarf could be trying to stop what he unleashed or just be trying to finish his focus.
If that is not your style:maybe the dwarf found the cistern started digging but was murdered by elves who killed him to make a profit on the water. The elves are making a fortune and the dwarf is trying to stop them from further violating the shrine/cistern. The PC could be the elves, relatives of one of the missing elves or the dwarf himself… etc…