Dean is not doing well, so Sam sneaks off for a clandestine meeting with Castiel. Reluctantly they agree their only source of information on the Mark of Cain is Metatron, but they soon find that Castiel's return to Heaven is barred.
Therefore they turn to Oliver Pryce (Richard Newman), a psychic known to the Men Of Letters, to contact their "inside man" - Bobby Singer, who is enjoying the afterlife in his own private paradise, reading the classics and downing cold ones.
They convince Bobby to sneak out and open the portal to Heaven from his side, so Castiel can get in and break Metatron out.
Meanwhile, Dean - with nothing to do - slides off to his favourite local watering hole and soon finds himself hustling frat boys playing pool. Unfortunately, while he's in the toilet, Rowena turns up and starts causing trouble.
After a futile confrontation with Dean she returns to Hell, claiming that Dean beat her to within an inch of her life, trying to stir up Crowley to exact some sort of revenge on Dean.
Unfortunately for her, the plan doesn't go quite as she hoped.
Structurally - by sheer coincidence - there were similarities between Inside Man and the episode of Agents Of S.H.I.E.L.D. that aired this week in the UK (A Wanted (Inhu)man), only Supernatural managed to pull off their parallel plot threads much more successfully.
Inside Man was an engaging blend of action and character material; none of which felt like padding.
It was great to see Bobby again, albeit for little more than a cameo, but a personal highlight for me was seeing Rowena getting her comeuppance (although I'm sure she'll be back soon to vent her wrath on her son and the Winchesters).
I realise there are still six episodes to go in this season, but there doesn't appear to be any progress on the main story arc - which I'm guessing is supposed to be Dean's battle with the Mark of Cain - except to say that the Winchesters are making no progress.
The brothers are running out of options and I'm sincerely hoping that the show doesn't just pluck a deus ex machina out of thin air at the eleventh hour to resolve Dean's situation.
Because we know it's all going to work out in the end, it always does on Supernatural, even if one or other of the brothers dies or is dragged off to Hell, but it's how these situations are resolved that keeps the show fresh.