Transfixing Daggers

You cast a flurry of 6 shimmering daggers forward. After reaching the end of the range of the spell, the daggers slow to a stop, reverse, and speed back towards you. Each creature in a 20-foot cone must make a Dexterity saving throw. Success or fail, a target takes 6d4 slashing damage. On a success, a target suffers no further effect. On a failed save, a target takes 6d4 slashing damage again, when the daggers return to you. (two seperate instances of damage, roll damage for both seperately)

Creatures within 5 ft. suffer a -2 penalty to the saving throw.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 2d4 for each slot level above the third.

Source: Metabot's Manual of Magical Maneuvers