From your earier post you stated 'There either 3rd or 4th level don't remember off head tempest cleric, wild sorcerer,champion fighter and a bard valor'
I'll work off 3rd level.
Tempest cleric
Wild Sorcerer
Champion Fighter
Valor Bard
For 4 x 3rd level PC's we get an xp budget of:
Easy: 300 XP
Medium: 600 XP
Hard: 900 XP
Deadly: 1600 XP
On the way through a forest (anywhere really) the PCs notice a clearing and hear voices (pick the PC with the highest passive perception). Upon investigation they see 1 figure in black robes (a
Cult fanatic, increase AC to 16 from scalemail under his robes) and 4 henchmen (1 hulking (str 16)
Thug armed with a greatsword (+5, 2d6+3 damage, multiattack) supervising the digging, and and
3 Bandits doing the digging) digging up a grave; a strange glow comes from the grave. The PC's get there just as the team finish their grisly work. If the PC's defeat the passive perception scores of the NPC's they get surprise on round 1 (this, plus the fact the PCs are at full strength, accounts for the difficulty of this encounter).
The cult fanatic uses
spiritual weapon and then targets heavily armored foes with
Hold Person, and the cowardly Thug uses this opportunity to strike if if he can do so (gaining an automatic critical hit on any held foes). The bandits target any obvious spellcasters. If the Thug dies, the bandits flee. If the cultist dies, the Thug fights on unless his men are also dead, at which point he surrenders. All he knows is that he he was hired by the cultist to escort him to this gravesite and help him with the excavation to recover some kind of powerful magical item. He only met the chap a few days ago, and is spooked out by him.
In additon to the normal gear, the bandits have 2d6 gp and sp each, the Thug has twice this much, and the cultist has 250 gp (payment for the mission for the bandits) two
potions of healing, and a map showing both the location of the graves, and a manor marked on the map (that none of the PCs have ever heard of before even with succesful knowledge checks). The manor is marked as 'the Manor of the black knight'. It is 2 hours travel away, but easy to find.
If the PC's investigate the grave, they see a human skeleton, clad in the tattered remains of a gown of white samite. Its skeletal hands bear a ruby ring (worth 50gp) - obviously a wedding band of some sort - and clutch a glowing [weapon - give it a cool name. Preferably something that the champion and cleric like to use]. The weapon is magical and deals an extra 1d6 lightning damage on a succesful hit, and gives off a glow as a lantern that can be surpressed or activated as a bonus action at will (requires attunement).
If the PCs touch the weapon, they trigger an ancient curse, placed on the weapon by the murdered woman whose skeletal remains they now stand before. Suddenly a ghostly apparition appears hovering over the grave; of a spectral woman with raven black hair covering most of her face and clad in white samite; a firey ruby ring adorns her finger.
Before they can act she wails out:
'You have all broken the bonds and now will carry the curse. At midnight, seven hours hence you shall all be struck down. You must track down my killer, the black knight, and put his soul to eternal rest, If you do so, the curse shall be lifted and [the weapon] shall be rightfully yours'
Tell the PCs that they suddenly feel an odd cold feeling come over them, as if someone walked over their grave.. and they all have the strong sense of impending doom. Whover is holding the [weapon] gets a momentary vision of a grand manor house, and for the rest of the adventure will always know the location to it.
After saying this she fades away, with the words
'Seven hours...' echoing ominously through the forest.
More to come...