'Mare of Easttown' director says Sunday's episode, which seems to finally reveal Erin's killer, may be his favorite because of the 'satisfaction' of questions being answered

• Warning: Major spoilers ahead for "Mare of Easttown" episode 6, which aired Sunday night.
• Director Craig Zobel loves this one: "The satisfaction of having questions ... answered is nice."
• Zobel, who directed all seven episodes, also praised Kate Winslet's "truly amazing" performance.

Warning: This post contains major spoilers for the sixth episode of "Mare of Easttown."

"Mare of Easttown" director Craig Zobel says that Sunday's episode of the show might just be his favorite, after last week's installment of the HBO thriller ended with a twist that left many fans heartbroken.

"I love all of the episodes. They're all my children, but I really like episode six," Zobel told Insider over the phone on May 13.

"The satisfaction of having questions start being answered is nice," he added, explaining why he's so fond of this one.

"Mare of Easttown" tells the story of Detective Mare Sheehan (played by Kate Winslet) who is trying to solve the murder of one teenage girl, Erin (played by Cailee Spaeny), and the disappearance of another, Katie (played by Caitlin Houlahan), while struggling with a few complicated issues in her personal life.

For five episodes, the culprit behind Erin's murder was on the loose in a town filled with suspects. That changed on Sunday's sixth episode when Billy (played by Robbie Tann), an older male relative of Erin, is revealed as her killer - and also her baby's father. (Although some viewers aren't convinced Billy isn't being set up or willingly taking the fall for the crime, given that there's another episode left to go.)

Prior to discovering who killed Erin, Mare also finally found Katie in the show's big, twisty fifth episode.

Katie, who'd been missing for over a year, was being held captive by a local man named Wayne Potts (played by Jeb Kreager) in his attic before Mare tracked down the abductor using license-plate numbers.

However, in the same May 16 episode, Mare also lost her partner, Detective Colin Zabel (played by Evan Peters), who died after getting shot by Wayne while rescuing Katie.

"Mare of Easttown" fans were particularly devastated by Colin's death and took to social media to say goodbye to the beloved detective (and Peters, a fan-favorite).

Unfortunately for fans of the show, Peters left no room for any possible return for his character in a conversation with The New York Times published on May 16.

"I like the idea that he gets shot because it's so real," Peters told the Times. "That's the way sickness and death is. It hits you in the most unexpected ways. You never plan to get sick. You never plan to die. It all just happens."

Zobel also praised Winslet's performance in Sunday's penultimate episode

In addition to discovering the identity of Erin's murderer, Sunday's episode also happens to be particularly emotionally-charged for Mare as she comes to terms with Colin's death, processes some difficult memories of her son Kevin's suicide, and works through possibly losing custody of her only grandchild.

"I think it has some truly amazing acting from Kate Winslet, in my humble opinion," Zobel told Insider, citing Winslet's moving performance as another reason why he "really likes" episode six of "Mare of Easttown."

Zobel says that his goal with the show was to make "a murder mystery that was enjoyable and fun to watch" and have Winslet portray "a contemporary woman that you see in real life a bunch, but maybe you don't always see on TV."

He told Insider he was especially impressed with how Winslet, who is British, has handled her critically-acclaimed Delaware county accent in the seven-part limited series.

"She was able to actually, like, jump in and out of it in a fun way," Zobel said of Winslet's accent skills.

"I think if I had been acting in this, I would probably learn how to do the accent and then just never not do it because I would be scared that I'd forget," he added with a laugh.

The "Mare of Easttown" finale airs next Sunday, May 30, at 10 p.m. ET on HBO.