Task: Question Answering
Input (English): Passage: After struggling with infertility, Anne finally succeeds in getting pregnant through invitro fertilization with her husband Jack. However, one night, Anne awakens to discover a masked intruder in her room. Terrified, Anne tries to escape, but the intruder chloroforms her into unconsciousness, rendering her helpless as he kidnaps her and takes her to an isolated house.
In the morning, Anne finds herself held captive by a couple named Frank and Helen. Helen has gone mad after her baby was aborted by Frank upon learning that it would have been born deformed. The procedure left her sterile, and he is now attempting to make it up to her by giving her Anne's baby. Anne recognizes Frank as a technician at her fertility clinic, and Helen later tells her that he secretly replaced her fertilized egg with one of Helen's instead. Frank stages a car accident with a horribly burned body to make everyone believe Anne is dead; Jack refuses to accept it and pressures the police to continue investigating, but after several months they dismiss his ideas. 
Question: What is the name of the character whose fertilized egg was replaced with one of Helen's?
Output (English): Anne.