In the upcoming 19th episode of "Once Upon a Time," viewers will be introduced to a young Cruella de Vil, who appears in a flashback segment of the episode, KSiteTV reports.

In the flashback segment, Cruella's tumultuous relationship with her mother is shown and viewers will see how Cruella's mother used her Dalmatians to terrorize her.

In addition to using her Dalmatians against her, Cruella's mother also locks her in the attic and her vulnerability and hopelessness grows until a mysterious stranger shows up in the attic and empowers her to challenge her mother.

Viewers will see how this mysterious person ultimately sways Cruella to become evil.

Meanwhile in Storybrooke, Regina is successful in stopping Gold from interfering in her plan to rescue Robin in New York until she and Emma discover that Cruella kidnapped Henry, which forces Emma to put a halt on her initial plans.

IBT claims that though the episode title "Sympathy for the De Vil" suggests that the episode will mainly focus on Cruella, it will actually center around Regina.

Viewers will get to see whether Regina will join forces with other villains or join the good side and link with the heroes.

On the last episode of "Once Upon a Time," Gold revealed to Regina that her elder sister the Wicked Witch of the West is not dead. Regina learns that not only is her sister alive, she is living with Robin and posing as his dead wife Marian.

After Regina's shocking discovery, Robin declares his love for her, which she reciprocates. However, Regina is forced to leave Robin in effort to save Marian, who is being possessed by her sister as a form of sabotage to her. 

IBT claims that in the upcoming episode, Regina will ultimately choose to stick to the good side and not join the villains.

This decision will inevitably cost her the loving relationship she could have potentially formed with Robin. It will also cost her the life of her son Henry, who might be taken captive by the villains.

"Once Upon a Time" Season 4 Episode 19 airs Sunday, April 19 at 8 p.m. EST on ABC.