Travel to Stratholme, in the north. Search the supply crates that litter the city and recover 5 Stratholme Holy Water. Return to Leonid Barthalomew the Revered when you have collected enough of the blessed fluid.
I look at my undeath as a malady, <race>. An illness that merely requires treatment; however, it is also a great blessing for the Argent Dawn. What better vessel to smite the heathens of the Scourge than through the undead?
I am revered by my colleagues because of the sacrifices I have made, but the accolades mean nothing to me.
If you are interested in assisting the Argent Dawn, then a job I can offer.
Venture to Stratholme and recover our surplus of holy water. Search the supply crates.
Well done, <race>. You have proven that while you are tolerant of others, you will stop at nothing to destroy the minions of Kel'Thuzad.