Retrieve a book for the mage who runs the arcane house

The mage who runs the local arcane house (get a name) will pay 80gp to any party who can help retrieve a book that’s gone missing.

With some prying, the mage will explain that they think the book was taken by their former partner. The book stolen was The Unique Umbra: a necromantic solution to undeath. The problem, the mage will explain with more prodding, is that their partner is an undead Wraith. While it may seem the partner is looking to undo their own death, the mage fears the magic in the book may actually strengthen them.

The mage can point them to a tower some miles outside of town where they used to walk with their former partner. The wraith may have taken up residence there.

If asked why the mage won’t go themself, they’re afraid their magic will be turned against them.

At the tower, the party will encounter the Wraith and a host of Specters (roughly one for every level of the party).

The Wraith is involved in a ritual involving the book. If no one attacks the Wraith, it will take them 4 rounds to complete the ritual. If the ritual is completed, a terrible power will seize the Wraith. The battle will stop while the Wraith draws a specter out of each PC. Each specter will fight its doppelganger PC with a spectral version of their own weapon (or just life drain against the spellcasters). These specters will fight along with the other specters.

If the ritual completes, the PCs could just try to steal the book and run for it. The doppelganger specters will chase them but the wraith and the others will stay behind. The Wraith now has the power to draw specters out of living beings and will remain an at-large threat to the town.