Most of this quest takes place on the facet of Tartarus although it begins in Trammel.
Start by talking to Oliver the Paladin in Trammel at the Trinsic Paladin Guild (just north from the Travel Coach).
Oliver will send you to Tartarus to speak to Elminster the old mage and will give you a book with directions to find him. Elminster will put you on a random path to obtain a Virtue Artifact which Oliver needs in return for Cleric Prayers and Paladin equipment. Samples of the equipment can ve viewed upstairs in the Trammel Trinsic Paladin's Guild.
Each segment of the quest must be completed within one hour and no break time is allowed between segments. Highly skilled characters with experience (or those with friends) could complete the quest in about one hour. Three to four hours is the absolute maximum.