Fridge Brilliance
- Lindsay's comments about Sandie during the bar confrontation hint that he suspected Sandie of at least being connected with the disappearances. Being a vice cop, he knew the area pimps and prostitutes well enough to notice when some of them went missing or changed behavior. Jack going missing was probably the start, coupled with the string of disappearances of customers who were sighted in the area around Sandie's house, may have been enough to clue him in that Sandie was up to something. The only thing holding him back from arresting her was a lack of evidence that could directly tie her to the situation.
- The information he gathers on Eloise also becomes more understandable in the context of his investigating Sandi, and likely suspecting Eloise was her granddaughter at first. He was probably trying to determine whether she could be a useful source of information (and considering he was waiting for her the same night she tried going to the police about her visions he might well have been planning on sharing at least some of what he knew before she started lashing out at him.)
- Lindsay's status as a vice cop who had to hang around prostitutes in the guise of a john also explains the bar staff's perception that he's a creepy ladies' man; presumably they would have seen him approaching prostitutes frequently when he was still an officer and drawn the wrong conclusion about his motives.
- A simple piece of Five-Second Foreshadowing when Eloise is talking to the Silver-Haired Gentleman for the last time: he's wearing a wedding band. Whether his wife is still alive or it's his Tragic Keepsake, it's enough to crack the image of "ladies' man" that other people associate him with. Which shows how people make assumptions based on prejudices and partial info, and miss what's right in front of them.
- Also, just before he leaves, he says he's not into "this line of questioning". A very cop phrase.
- There are some subtle visual clues that hint that the Silver-Haired Gentleman is not an elderly Jack.
- The Silver-Haired Gentleman has vivid blue eyes, a trait shared with Lindsay and not Jack.
- The Silver-Haired Gentleman lacks the facial scar from the deep scratches that Sandie manages to give Jack before he (apparently) kills her.
- The fact that the "Sage Barmaid" is so often seen deep in conversation with the Silver-Haired Gentleman is also a hint that he's not a sleazy, murderous pimp, as you'd think she'd be wise enough to steer clear of him.
- The boorish man at the Café de Paris calling Sandie a whore out of the blue makes a lot more sense after the reveal that Jack is a pimp. The boorish man probably legitimately thought she was a prostitute. The fact that Jack is seen laughing with the man later shows that he didn't actually take offense to the man's insult and about his Engineered Heroics.
- Although a member of Ellie's class, John isn't presenting any designs at the fashion show in the end. Given that he was stabbed and nearly died, he likely had to skip the rest of that semester.
- Edgar Wright's thesis about his own obsession with the 60s is that it's the decade when his parents were young and he just "missed" (being born in 1974). Ellie's classmates are in their very late teens and early 20s, so they are more nostalgic about the 80s and 90s when their parents would have been young. Ellie was raised by her grandmother so Ellie's nostalgia ended for a full generation earlier.
Fridge Horror
- Mrs. Collins mentions that she's had numerous tenants in the upstairs room for years. How many others might have been sensitive like Ellie, noticing something horrifyingly wrong with their current apartment? Did they just nope out of there thus explaining why Ms. Collins has a history of tenants up and leaving in the middle of the night?
- Ellie was definitely not the first one to flee the apartment in the middle of the night.
- Did all of them actually just take off in the middle of the night, or was that just the line she usually gave when she needed to kill a girl who seemed like she was getting suspicious of something about the room but hadn't shown the same apparent instability as Eloise for her to feel safe just letting the body be found and passing it off as suicide. She seemed very comfortable dosing out poison for someone who's supposedly only killed with a knife before.
- While not necessarily hitting triple digits, Sandie's home was apparently filled with enough bodies that the spirits crowded the room during the climax. Once the firefighters and police investigate the home, odds are they'll find at least double-digit bodies in the wreckage. She may have been one of London's most prolific modern serial killers, but still managed to take out dozens of men, and may have even escaped punishment if not for Ellie.
- The barman at the Cafe du Paris tells Sandie to speak with Jack about her wish to become a singer. This raises the unsettling question of whether the barman (as well as the other staff and patrons) was aware of Jack's pimping and saw no issue with telling her to approach him, or if Jack's charming facade has successfully hidden his criminal activities even from people he might interact with frequently—or, worse, if the staff are involved in his process of recruiting young women.
- Mrs. Collins states "bless" sarcastically after mentioning others being concerned of Ellie's wellbeing while attacking her. Implying her bitterness that no one ever cared for her own suffering that may have been easily avoided if anyone had taken notice.
- The end credits of the film feature static shots of street corners in London while "Last Night in Soho" by Dave Dee, Dozy, Beaky, Mick & Tich plays in the background. Not that horrific, until you think about what Ms. Collins says earlier in the film - "This is London. Someone has died in every room in every building and on every street corner in the city." You could interpret the quiet, dim shots of London at night as implying that every shot you see is the site of someone's death. Brrr.
