Six gruesome blades forged from dwarven blood in the pits of ancient bol-Pakash. Six knives the dwarves wish never existed.
Maddoc sat amid a pile of unrecognizable corpses. Men, Dwarves, Orcs, you couldn't tell. He periodically took a stab at one with his new knife and screamed, "STOP LAUGHING AT ME!"
A dark dagger of song, forged for vengance. It shall have that vengance.
A dagger that makes the user think that he is invisible.
Draw the party together as debtors to the local lord, king, head of the thieves guild, or mercenary clan, who is forcing them to work together to pay off their debts.