You fire a bolt of brightsteel that will force a Dexterity Save = To your spell save DC from 2 creatures in a line equal to the spell's range. When you cast the spell you must designate if it is a Bladed Bolt or a Restraining Bolt.
A Bladed Bolt will deal 2d8 damage on a failed Dex Save and pass through the target and strike a target behind them for 1d8 damage if they also failed the save. Or half damage on a successful save.
A Restraining Bolt will dead 2d4 damage on a failed save and pin the target to the ground or a wall or object behind them, restraining them. On a successful save they take half damage and are not restrained.
When you cast this at higher levels you fire an additional bolt. You can target multiple creatures to the same effect as listed above, but hitting one target with multiple bolts will cause them to have disadvantage against the Dex Save.
* - (A shard of steel and a piece of copper wire)