Ariel is one of the Invid larvae that had evolved into humanoid form to act as a "simulagent." While being transported for implantation among the human population, she is accidentally lost by the Invid. Scott Bernard's resistance group finds her at the scene of an Invid attack. They believe this beautiful young woman to be an amnesia victim, still in shock and unable to talk due to the horrible trauma that she had endured. Scott, Lancer, Rook, Rand and the others adopt her into their makeshift family. Scott's past returns to haunt him as the group calls the girl "Marlene", the same name of his dead fiancée.
Ariel really has experienced trauma - though the Invid can sense her presence, she has literally been abandoned her own people. Now, as "Marlene," she is unwittingly spying on the very people who are now caring for her. She is not even aware of her Invid origin as she grows to trust and care for her companions, even falling in love with Scott Bernard. It is only a matter of time before she ... and they ... discover her true identity.
Marlene is suffering from amnesia when she is recovered by Scott’s resistance group.
Unaware of her Invid origins, Ariel accepts her new human identity as “Marlene.”