IT: Welcome to Derry Episode 1 dropped major hints about what really happened to Lilly Bainbridge's father, and it's pretty tragic. The prequel series from HBO Max introduced a new group of kids tormented by Pennywise in 1962, and one of them is Lilly (Clara Stack), who harbors a mysterious past. Welcome to Derry revealed that Lilly was close friends with Matty, one of Pennywise's victims in Episode 1, which kickstarted the prequel's story.
Similar to the original Losers' Club from the IT movies, Lilly was also bullied by her peers from school. She also suffered a traumatic stay at the Juniper Hill Asylum, following her father's tragic death. Given that Pennywise always wanted to exploit one's weaknesses and vulnerabilities, the horrific creature used the death of Lilly's father as a weapon to further torment her.
What Happened to Lilly's Dad in 'IT: Welcome to Derry'?
IT: Welcome to Derry Episode 1 pulled back the curtain on what really happened to Lilly’s dad. At the 23:31 mark, a flashback showed Lilly and Matty (the victim of Pennywise's cruelest trick) talking about the former's dad, leading to Lilly finally opening up about the events that led to her father's death.
Lilly's father was working at a jarring plant in Willoughby. At one point, Lilly and her mom went to pick him up, but she forgot her mood ring inside the factory so her dad went back to get it:
"My mom and I went to pick up my dad. He worked at the jarring plant out on Willoughby. You know, pickles and stuff. We were leaving the factory when I realized I’d forgotten something inside. This... This mood ring I just bought at the five-and-dime. It was just a cheap, stupid toy, but-- but he went back to get it."
Unfortunately, one of the machines inside the factory "jammed up," prompting Lilly’s father to swoop in and fix it. However, her dad didn’t realize that the machine’s power was still on, and it was too late because his body ended up being mutilated after he got stuck between the gears:
"And I don’t know-- I don’t know, one of the machines jammed up. It wasn’t even his station, but-- but my dad... he always wanted to help. They said he climbed into the gears. I guess he thought he’d killed the power, but... when the foreman realized it was on another station, it was too late. If I hadn’t made him go back..."
The death of Lilly‘s father took a toll on her. She blamed herself for it, which led to her downward spiral. This also explained why she was sent to Juniper Hill Asylum. What made matters worse is the fact that her schoolmates bullied her over her father's gruesome death, using pickle jars as a means of insult toward her. Some of her classmates even spread rumors that her dad's body parts were found in pickle jars all over Maine, while others called her "Looney."
How Pennywise Used the Father's Death to Torment Lilly in Episode 2
After Lilly witnessed firsthand the brutal murder of her newfound friends in Episode 1's wild ending (which included Teddy Uris, a relative of original Losers Club member Stanley Uris from IT), Pennywise continued to haunt Lilly, knowing that she is still an easy target because of her fear and guilt over her father's death.
Pennywise used pickle jars as a way to torment Lilly while she was inside the supermarket. IT surrounded Lily with several shelves of pickle jars before a good chunk of it fell to the ground, revealing tons of rotten body parts (assumed by many to be Lilly's father).
The mutilated body parts then transformed into a living, breathing creature that attacked Lilly. While Pennywise didn't kill Lilly, this was more than enough to show the citizens of Derry that she was still a troubled little girl, leading to her unexpected fate in Episode 2's ending, where she was sent back to Juniper Hill Asylum.
Sending Lilly back to Juniper Hill could be part of Pennywise's grand plan in Welcome to Derry because the creature could use her fractured psyche in two ways. The killer clown could further torment Lilly with visions and illusions, but no one would believe her because they would only deem her crazy.
Another way Pennywise can take advantage of Lilly is by possibly using her as a scapegoat, similar to how the clown used Henry Bowers in the first movie as the one blamed for the mysterious happenings to the kids in Derry.
