Long ago, Optimus Prime was forced to abandon Blackarachnia in the caverns beneath the surface of an alien world. There, she found herself surrounded by a terrifying horde of bizarre spiders, and she was forced to reformat herself based on the strange organism to survive. The experience twisted her, drove her away from the Autobots, and left her with an undying desire for revenge on the former ally who left her to her fate. She has come to Earth in search of Optimus Prime, and she will not stop until she has destroyed him and all he holds dear.