Mysteries upon mysteries continue to cast a pall over the seemingly idyllic town of Riverdale. Though some new clues and revelations have been doled out in the last couple of episodes, the murder of Jason Blossom remains unsolved and its ramifications continue to seep into every facet of the town and its denizens. However, other questions lingered beyond the Blossom murder, and this week's episode, 'Chapter Four: The Last Picture Show', addressed the most lurid and scandalous affair happening in town: Miss Grundy's relationship with her student Archie Andrews. Even more so, Riverdale asked and answered this week's big question: Who is Miss Grundy?

Last week, while conducting their own investigation for the Riverdale High newspaper the Blue and Gold, Betty Cooper and Jughead Jones interviewed their classmate Dilton Doiley, who was at Snakewater River the morning Jason Blossom was believed to have died. (We've since learned that Jason was actually shot and died a week later, on July 11.) Dilton dropped the bomb that he spotted Miss Grundy's car at the river. Betty, aware that Archie was also at Snakewater River that morning, put two and two together and came up with: Archie's involved with his music teacher. (Jughead, however, already knew this but didn't tell Betty that he knew -- what a tangled web teens weave at Riverdale High.)

When Betty, at Pop Tate's Chock'lit Shoppe with Jughead, Veronica Lodge, and Kevin Keller, spotted both Archie and Fred Andrews enter with Miss Grundy -- the Andrews men were innocently taking her out to dinner as a thank you for believing in Archie's musical talents -- the milkshakes hit the fan. Betty (joined by a curious Veronica) immediately confronted Archie, who admitted he was "together" with Miss Grundy in a "relationship." It was a spectacularly surreal moment for this classic comic book love triangle; Betty and Veronica making Archie spill the beans about sleeping with his teacher.

Betty, however, couldn't abide by Archie's pleas to leave Miss Grundy alone. She immediately put her skills as an investigative reporter on the case of Who is Geraldine Grundy? What she learned were not the details about Miss Grundy that longtime readers of Archie Comics have come to expect.

Classic Miss Grundy

Debuting in Pep Comics #30 (1942), Miss Grundy, as she's been classically depicted pre-Riverdale, is a white-haired older lady (in some early comics, she was bald and wore a wig, which she'd then lose to her embarrassment) who teaches English and math at Riverdale High. An interesting note is the origin of her name Miss Grundy, which is derived from "Mrs. Grundy," a 19th century slang term used to describe a prudish woman.

Geraldine is Miss Grundy's accepted first name, but some comics have given her different first names like Amanda, Elizabeth, and even Gertrude. Though often depicted as a hard-driving teacher, Miss Grundy is a beloved figure at Riverdale High, who is also an alumna of that venerable institution.

Riverdale revealed that Miss Geraldine Grundy did exist in the town at one point and was a white-haired older lady who wore a red blouse with white polka dots -- the spitting image of her comic book counterpart. However, it seems the "real" Miss Grundy lived in Riverdale a long time ago as Betty didn't remember her at all when she discovered her obituary.

Riverdale's Miss Grundy

Riverdale had their cake and ate it too with their version of Miss Grundy. Remaking this character into a young, hot teacher who seduces Archie into a sexual relationship raised a lot of eyebrows, but the show deftly subverted at least the "changing the classic character" side of the controversy by revealing their Miss Grundy to be an imposter. As Betty found out when she and Veronica did some breaking and entering into Miss Grundy's Volkswagen Beetle, the imposter is really Jennifer Gibson from Minnesota. Once Betty and Veronica made Archie aware of her true identity, Archie confronted her for answers.

To hear her tell her tale, Jennifer was a former cello student at Julliard and once pursued her music career, auditioning at Carnegie Hall and Lincoln Center but she didn't make the cut. Jennifer was once married, but her ex-husband battered and abused her. She fled Minnesota and claims she was a music teacher at different schools like Seaside High and Centerville High but they were temporary placements. One year ago, she arrived in Riverdale and assumed the identity of the late Geraldine Grundy, with fake Facebook and LinkedIn accounts to match. How she found out about the previous, elderly Geraldine Grundy to assume her identity is yet unknown.

'Chapter Four: The Last Picture Show' blew the lid off the Archie-Grundy scandal when Betty's mother Alice read her diary and then told Archie's father. Altogether, Alice, Betty, and Fred confronted Archie and Jennifer, with Alice, the editor of the town newspaper, threatening to publicly expose the affair. Ultimately, Jennifer decided to leave Riverdale. And yet, despite the dissolution of her affair with Archie, old habits die hard, judging from the way Jennifer ogled other young, male Riverdale High students on her way out of town.

All's well should have ended well in the solved mystery of Miss Grundy and her secret past. Except for one more thing about Jennifer Gibson that Betty discovered.

Miss Grundy's Got a Gun

Betty and Veronica discovered a handgun in Jennifer's car. Her owning a weapon isn't entirely unusual in and of itself, as someone on the run and hiding from an abusive husband who might possibly still looking for her. What makes the gun possibly smoking is what Jennifer told Betty while being interviewed for a fake story in the school newspaper: prior to Archie, Jennifer taught the late Jason Blossom last year. (Betty trying to get Jennifer to reveal an illicit affair with Jason by dropping how "cute" Jason was garnered a response that Jennifer "doesn't think of her students that way.")

Until forensics reveal the bullet that shot Jason didn't come from that gun, Gibson is now on the list of suspects in the murder of Jason Blossom, at least in the mind of the audience. Riverdale's Sheriff Keller is yet unaware of this fact as he has his own problems, namely someone breaking into the Keller home and stealing the wall of suspects the Sheriff had assembled about the Blossom murder.

We know it was Dilton who fired a rifle on the morning of July 4th that Archie and Jennifer heard when they were at Snakewater River together, but did her gun fire the fatal head wound on Jason Blossom? Is Jennifer Gibson Jason Blossom's killer after all? If so, even after skipping town, it would mean we haven't seen the last of the former Miss Grundy.

Next: Archie Comics & WB TV Deal Sets Stage for Riverdale Spinoffs

Riverdale airs Thursdays @9pm on The CW.