Torrs Chain

Make a melee attack with a weapon, against a creature within spell range, otherwise the spell fails. On hit, target takes the attacks normal damage and a small bolt of electricity leaps from the target to a different creature of your choice within 5ft of the target. The Second creature takes lightning damage equal to your spellcasting ability modifier.

The Spell's damage increases when you reach higher levels. At 5th level the melee attack deals an extra 1d8 lightning damage to the target, and the lightning damage to the second creature increases to 1d8 + your spell casting modifier. Both Damage Rolls increase by 1d8 at 11th level, and  another 1d8 at17th level.