Previously on Arrow - which was just this frickin' minute picked up for a second season - Ollie (Stephen Amell) began to suspect that his mum Moira (Susanna Thompson) was not the squeaky-clean business mogul she's posing as when Felicity Smoak (Emily Bett Rickards) handed him a list - identical to his father's - that was previously in his mother's possession...
The level-headed Diggle (David Ramsey) is quick to point the finger at Moira, but Oliver won't believe his ma's a wrong 'un, not even when she burns the book and tells her son to "stop asking questions" - come on, Ollie, we know you'll never top Batman as the World's Greatest Detective, but there's no excuse for this kind of sloppiness.
Diggle is intent on keeping an eye on Moira, but his own efforts to ascertain her guilt prove fruitless for a long while - we love you, Dig, but you're about as good a gumshoe as Ollie. Still, Dig ultimately manages to record a shady and incriminating meeting between Moira and John Barrowman's sinister smarmster Malcolm Merlyn.
"You bugged my mother?!" a horrified Ollie asks, in a manner that suggests he's accusing Diggle of doing much worse. Still, his anger is soon vented in a different direction when the recording makes it clear that Moira may have played a role in Robert Queen's death...
Elsewhere this week, the unlikely-named criminal Cyrus Vanch stalks the streets of Starling City again following a surprise prison release - he's played by cult supremo David Anders, he of Heroes, Alias, 24, Once Upon a Time *and* Vampire Diaries fame.
It's just as well that Arrow cast a familiar face here, since Vanch is a pretty uninteresting foe as written - it's only Anders's performance that keeps him just about the right side of entertaining.
Tommy (Colin Donnell) - Laurel's doting rebound - is still doing his best to woo her, hiring multiple chefs to cook a lavish meal. "I'm trying to figure out how to get a vicious criminal back in jail," she snipes, shooing him away like an unwanted puppy - poor Tommy really is too good for her.
Laurel (Katie Cassidy) unwittingly reaches out to her ex when she contacts the Hood for assistance in putting Vanch away again, and though her cop dad Quentin (Paul Blackthorne) has been taken off the 'Hood' case, he's soon back at it like a bloodhound when his tap on Laurel's 'Arrowphone' picks up his daughter's cry for help.
Quentin conspiring against his daughter, Moira plotting against her son - Arrow isn't exactly a showcase for good parenting skills at the moment.
The fall-out from Quentin's latest clash with Oliver puts Tommy and Laurel at loggerheads when he learns that she's been hanging with "a murderer" for months. You won't believe it, Arrow maniacs, but Tommy actually stands up for himself here - well, a bit. It's progress.
Tommy also clicks pretty fast that Laurel has an "infatuation thing" going on with the Emerald Archer - it's just a shame that he chooses Oliver as a shoulder to cry on…
Laurel's attraction to dangerous men lands her in trouble, as Tommy predicted, when she's snatched by Vanch, forcing Quentin to turn to his nemesis, the Hood. Oliver ultimately stops Quentin from shooting his daughter's kidnapper dead, with the line, "I'm the vigilante, you're the cop!". We're not quite sure why Ollie thinks it's only OK for him to murder villains - perhaps he considers his 'nemesis' Quentin to be a better man than he is?
Laurel is saved but refuses to forgive her father's betrayal, while Oliver decides to cut ties with Laurel as the vigilante in order to keep her safe, leaving poor puppy-dog-eyes Tommy to comfort his tearful missus...
Ordinarily, Oliver's exploits in Starling City leave his island flashbacks in the shade, but this week, events in the Pacific were what really grabbed our interest - chiefly because these scenes included the long-awaited debut of Slade Wilson - Manu Bennett endowing the part with the same gravel-voiced brutishness that he brought to the role of Spartacus hard-nut Crixus.
Unlike last week's big-name guest star - Fringe star Seth Gabel - Bennett is well-cast as Ollie's new bad-ass ally and his early swordplay scenes are a nice nod to his best-known work.
Following on from his early experiences with Yao Fei, it seems pretty clear that Oliver's time spent with Wilson will play a big part in forging him into the toughened vigilante with rock-hard abs that he is destined to become. For right now, we're intrigued by Slade and excited to see what link he might have to the Deathstroke we've already met.
'Betrayal' is a top-notch episode of Arrow - one that's all the more welcome following last week's slightly dodgy instalment. There's action, intrigue, and while Vanch is pretty weak as villain-of-the-week, the ongoing Moira Queen sub-plot and the introduction of Slade Wilson means that there's plenty of interesting foes for Oliver to tangle with.
Arrow continues on Mondays at 8pm on Sky1.