When cast, the spell manifests in the form of linear white light connecting the palms of each of the Charmed Ones, thus forming a triangle of light that trapped Parker inside.
In Out of Scythe, the Charmed Ones cast this spell to defeat Parker Caine who was after the last shard of the Scythe of Tartarus. However, before the Charmed Ones could finish it, Parker pulled out the two other shards of the scythe, causing the last shard to be pulled towards it. The shard hit Mel in the back and broke her concentration, ending the spell itself.
We call upon Theia, Goddess of Light.
She who persisted, she who could fight.
Give us the strength to brighten this night.