Traveler's End (Heroic One Session Campain)

A one session campaign about surviving a zombie attack on Traveler's End by the necromancer searching for the relic being held by the noble whom hired the party as body guards for the highest price. A few powerful Knights of the Freesoul Order help and tell the party that they will have reinforcements in four days. Can the party outwit the necromancer as he plots and attempts to achieve his goal behind stone walls surrounded by a horde of the undead. This is a campaign from my private services and i am using it to learn the world anvil systems while creating a cool one shot campaign.