This is the last quest for the Valentine's Day rewards.

For horde, the quest line to get this begins with a Deathguard Tor (http://classicdb.ch/?npc=16003) located right outside the Undercity Zeppelin (Alternately, Orok Deathbane (http://classicdb.ch/?npc=16007) in Ogrimmar outside the bank, and Temma of the Wells (http://classicdb.ch/?npc=16008) in Thunderbluff.) . He will give you a card to give to Elenia (Quest named: "Dearest Elenia,"). You give this to Elenia located around the UC bank (http://classicdb.ch/?npc=16004).

This finishes this part of the quest line, and a quest giver (Fenstad http://classicdb.ch/?npc=16108) right next to her will have a quest (Quest named "Fenstad's Hunch"). He sends you to Apothecary Zinge (http://classicdb.ch/?npc=5204) located at the far back of the Apothecary District. She gives you the quest "Zinge's Assessment", where you return to Fenstad. Fenstad rewards you with a "Box of Chocolates" and a "Handful of Rose Petals".

The next quest is "Tracing the Source" (http://classicdb.ch/?quest=8982), where he sends you to the Inn Keeper located on the top of the inner ring. Inn Keeper Norman (http://classicdb.ch/?npc=6741) then sends you to Mara Rennick (http://classicdb.ch/?npc=16109) located at the UC Tailoring Shop (the quest is also named "Tracing the Source" http://classicdb.ch/?quest=8983).

Finally, she gives you "The Source Revealed" (http://classicdb.ch/?quest=8984), where you're asked to find Apothecary Staffron Lerent (http://classicdb.ch/?npc=16107). Lerent is located near Ravenhold Manor, which is in Hillsbrad. Once you're in the manor, head past the farm, (past the wall) up the hill, and down it, procede northeast until you see him.

Turn in the quest, and MAKE SURE to click the cauldron nearby. The quest giver makes no indication of this, and this is how you get the reward. The cauldron gives a quest "A Bubbling Cauldron" (http://classicdb.ch/?quest=9029), and you get your choice of one of six vanity chest pieces, between red, blue, and purple "Lovely Dress" and the same colors for "Dinner Suit".

The final part of this is identical for both factions, so other then the running around (I believe the quest has you running around Stormwind to much the same effect as Horde do in UC) you finish at the same spot. There typically seems to be people ganking due to the likelyhood of others showing up to get their reward, so watch out if you're on a PvP server, particularly since the cauldron isn't terribly obvious.

The "Lovely Black Dress" (http://classicdb.ch/?item=22279) isn't rewarded through this but is instead a rare gift given when turning in Love Tokens.