Transposition

You attempt to study and replicate the casting of a spell you witness by a creature within range. If the creature is casting a spell of 2nd level or higher, the spell fails and has no effect. If it is casting a spell of 1st level, you mimic the arcane art of the spell's casting, and on your turn you may use your action to cast that spell without using an additional spell slot. If you lose concentration before you can use your action to replicate the effects of the spell, you cannot do so on your turn.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you may attempt to replicate a spell that is of one spell slot lower than the spell slot you use cast this.