Instead of one narrative, I'll be enumerating the elements of the show that, for me, stood out the most or are worth talking about.
Visit the photos section for ep stills

THE 1930s
I think that, with the singular exception of Hyde School Reunion which is an 80's throwback, this was the only time Charmed was able to do an era/ decade theme without the element of time travel or flashback.

They've done the Middle Ages, Colonial Virginia, 1920s (twice), 1940's (Leo), 1960s and 1970's.

THE MALTESE FALCON
Charmed writers obviously drew inspiration from the 1941detective mystery film, The Maltese Falcon where Humphrey Bogart plays a detective in search of a statuette. Film critics say this film kickstarted the dark film noir genre in Hollywood.

The MF is derived from a 1929 novel by Dashiell Hammet with the same title. The book was made into film twice -- 1931 and again in 1936 -- before the more popular H. Bogart one.

PAIGE
The Magic School headmistress was certainly in her element here. I like how Paige took charge of the situation -- murder at Magic School -- and took responsibility for the safety of the school. While I was never fully happy with her taking over the school to begin with (don't hate me but i didnt really think she was qualified), i think that she showed her mettle in this ep...

BRODY
Another cop comes to the rescue of the charmed ones. Have to say that i'm glad it's him for this ep and not Darryl. With regards to Paige and Brody, well, cheesy pre-kiss lines aside, they look cute onscreen. Plus, Brody can hold his own and doesnt need to be a love interest in order to exist in the Charmed universe. After Glen and Richard, this is a refreshing difference, i think.
I just wish Kerr Smith didnt remind audiences so much of Cole. The hair, the suits, it's all so distracting!

PHOEBE
Cupid works alone --- whaat?
For someone just emerging from yet another aborted relationship (with Leslie), why is Phoebe suddenly playing matchmaker? I'm just glad to say that this compulsion fizzled out as quickly as it started.

PIPER AND LEO
I like how Piper is able to sense something amiss with Leo and is acting on it. (Unlike how Phoebe was completely oblivious about Cole's Source-half in Season 4.)
This is one of the plot twists that i'm really excited about for several reasons -- not least of which is the fact that it heralds another opportunity to see Holly in another topnotch dramatic performance.

FAVE SCENE:
Scene where Paige enters the interrogation room with a gun to save Brody from the dirty cop beating him up. As soon as Brody took control of the situation, there's a moment where Paige throws her own revolver aside with such an exaggerated flourish -- so funny!
And the quirkiness is very season 4 Paige -- something i've missed

FAVE LINE:
"And why is the G silent?"