You touch a piece of ammunition or weapon with the thrown property, imbuing it with crackling lightning energy for the duration.   The first time you attack with the empowered item, it transforms into a bolt of lightning, and when fired blasts out from you in a line 100 feet long and 5 feet wide. Make the weapon’s attack roll against each creature in that line, (Using the same roll against each creature) dealing 4d8 lightning damage on hit, and half as much on a miss. This damage roll does not add any modifiers or bonus associated to weapon attacks. The lightning ignites flammable objects in the area that aren’t being worn or carried.   Once an attack has been made with the piece of ammunition or weapon, the spell ends.