Jessa is a female Estherian who has journeyed with her father to find an ancient artifact, the Wraithring.
The player meets her in the Blightbogs in Act III, where she can be found standing alone outside the Rotting Crypt.
Jessa offers the side quest The Wraithring, where the player must discover the fate of her father who has wandered into the Rotting Crypt.