Situation:
A player is wearing magic armor that turns him invisible (DM describes "as the spell").
He grabs a wand, and his Pixie familiar casts Fly on him.
So he dashes 120' up a stairwell, passed the other players who only see a flying wand (player failed roll to see if wand would turn invisible), out of the dungeon, and 50' into the air and out of the other players' sight.
A PC wizard (one that the wand just fly by) casts Dispell Magic to stop it.
Dispell Magic says, "Choose one creature, object, or magical effect within range. Any spell of 3rd level or lower on the target ends."
Both Fly and Invisibility are 3rd or lower.
If you were DM, what would happen?