The point of no return.

The seeds were planted and John awoke, climbing out of her shell reborn. She looked around and everything had a tint of green. She listened as a voice called out to her, "Feed me..." It was Andrea and the command boomed in her ears. The call was too strong. She saw it in her sister, who had been emerged from her own shell and like John and Mrs. Juniper before them, completely ensorcelled by the talking plant's commands.

The plan to double their power with a second seed had backfired and now they were the plant's thralls, bid to drain the world of human life and enslave the women to plant more seeds. They produced tendrils of their own and spread their reach throughout the school. Prom was ruined. Everyone was taken and drained or converted. The sisters stretched on to the larger city. It would be a matter of days before the populous was either plant feed or servants to Andrea.

The magical plant grew with each victim it took, becoming a towering size at the cost of the local population. Other cities organized to fight the giant flower, but it was too late. It swatted down jets and tanks with ease as it uprooted itself and moved on to the next viable food source. Cities fell to the invading creature who sent forth its ladies to drain the cities of its will before treading in to reap in its rewards.

Humankind was doomed. The last vestiges of its existence crumbled under the growing roots and vines of the conquering plant life. The girls became more plant than people, all ruled by the gigantic overlord, Andrea.