The Grift

The Ghost Ship of Anvil
1) Speak with Varulae on the deck of the Serpent's Wake in Anvil Harbor.
   She asks you to retrieve her Crystal Ball from the cargo hold of the haunted ship.
3) Defeat the Spectral Sailors or run past them making your way down to the hold.
4) Return Varulae's Crystal Ball to her, she rewards you the "leveled" cutlass, Redwave.

Alternatives

Varlaue is bad Spirits are bad (The ball is cursed and Varulae curses you)
1,2,3) Same
4) When you pick up the crystal ball you are immediately cursed and you can't remove it from your inventory
5) Return Varulae's Crystal Ball to her, She says she doesn't want it, she reveals that she put a curse on the crystal ball and anyone who touches it will be turned to a wraith

Varlaue is bad Spirits are bad (The ball is cursed and Varulae curses you)
1,2,3) Same
4) your "perception"/"intelligence"/Conjuration skill is high enough you notice it is a trap (the ball is cursed) so you dont pick it up
5) you return to valarae and tell her that you killed all of the spectres and that she needs to grab the ball
6) you escort her to the ball, before she grabs it, she turns on you and attacks you kill her and taker her loot

Varlaue is ignroant Spirits are bad (The ball is cursed and Varulae helps you remove the curse)

1,2,3) Same

4) When you pick up the crystal ball you are immediately cursed and you can't remove it from your inventory

5) When you return it to Varulae she gives you another quest to remove the curse 

(and the ball (with the curse) suddenly becomes a valueable Boost

Varlaue is bad,(a necromancer) Spirits were betrayed murdered crew and spirits want revenge 
1,2) same
3) as soon as you enter the ship the doors are locked and the ghosts approach you and let you know that they were trapped in the ship by Varulae, and that she locked them in the ship and sealed the door so they all died (resorted to cannibalism)
As much as the spirits want to feast on your soul, they want revenge on varlaue more,
you can:
4i) agree and help them get revenge, (lift the bind, allow the cursed spirits to possess the crystal ball), carry the crystal ball (which cursed now hurts you while cvarrying) then sneak and pickpocket Varlae (while she is asleep) to give her the cursed crystal ball (then the spirits attack and kill her)
4ii) fight them and steal the ball which gives random perks, confront Varlae and either
5i) let her live if she gives you some important loot / information
5ii) kill and loot her corpse

Examples of Grift "templates"
House Sitter (Bodyguard) entrapment
Heist (and then double crossed) i.e. they leave you to take the fall
Fencing stolen goods
Carvan Robbery (could be disguised as Guards, Rival Gangs, etc.)
Duel
Guard some item (and you have option to steal it yourself)
Frame -> Breaking and Entering steal item (i.e. signet ring, guard outfit) perform crime(i.e. murder)and plant evidence
Help a prisoner escape
Kill/Intimidate witness
Assasination
Pickpocket
Forgery
Espionage
Reconnaissance ("sell" information after eaves dropping)
Intercept Messenger , forge note, disguise as messenger
Be a messenger (either look at note or not) but the note could implicate you
Gambling Cheat
Double Cross with help of Shills