The mid-season finale of Arrow is aptly titled "What We Leave Behind" because what we are left with, 9 episodes into the 5th season, is…what? I'm not quite sure. Let's work this out, shall we? But first – the recap.

Prometheus sharpens his blades as Evelyn a/k/a Artemis a/k/a Sellout Arrow delivers pictures and intel on Team Arrow.  It's a holly jolly Christmas as Mayor Oliver Queen and baby sister Thea throw a holiday party for their staff where the two of them can do a 'last week on Legends of Tomorrow' briefing for those in the audience who sat out the Invasion! crossover finale. Felicity and Billy a/k/a Detective Boyfriend are there to greet Curtis a/k/a Mister Terrific and his husband Paul a/k/a 'baby' and she immediately blows Curtis' cover story about all his bumps, bruises and late nights. Meanwhile the rest of Team Arrow deck the halls of the Arrow Bunker with Diggle and the late arriving Evelyn (had to drop off that good dish with Prometheus; you guys get Family Dollar stockings).

Paul leaves the mayor's bash in a huff with Curtis trailing behind and Prometheus nipping at their noses, slinging a throwing star, a beatdown and a dagger to Curtis in one camera move. The star used on Curtis leaves a drug in his body that traces back to Oliver's infamous list (cue the flashback) and crooked pharmaceutical tycoon Justin Claybourne. Retracing those memory berries, the Team confronts Prometheus at Claybourne's old factory where Aretemis reveals her duplicity. If he knows Curtis is connected with Green Arrow, then everyone is in trouble which means it's all hands on deck and everyone to their respective safe zones. A rooftop tête-à-tête with Thea, rocking her Speedy reds, reminds Oliver of a conversation with Felicity from way back when (roll that beautiful flashback footage) which clues him on the whereabouts of Prometheus. Leaving the crew to stew, the Green Arrow returns to the place of his first run-in with Claybourne, where Prometheus – revealed via analysis of cremated ash to be DNA-linked to Claybourne – has staged the bodies of the fallen cops in his wake in exact reenactments of the thugs The Hood took out so long ago. Fisticuffs and kicksicuffs ensue, a swing into another staged hall of mirrors and Green Arrow is lost. Which one is Prometheus? He catches the actual from the reflections and puts 3 arrows in him, top speed. Prometheus falls. With his blade duct-taped to his hand – oh no! It's not Prometheus; it's Detective Boyfriend Billy, who was captured by Prometheus earlier just for this occasion. Now he's dead and Oliver killed him. At Arrow HQ, Oliver relates the details of his encounter to Felicity and the others, who understand that this was Prometheus' doing, not his. Oliver, at his reporter girlfriend's apartment, doesn't totally agree with their assessment. Curtis is heartbroken because his husband leaves him because he didn't marry a 'vigilante.' Felicity is heartbroken because her Detective Boyfriend is gone. Diggle falls for one of the oldest tricks in the books – a cry for help from a loved one – and is apprehended by the feds. And Oliver is struck dumb when he returns to HQ to find a seemingly healthy and incredulously alive Laurel Lance.

THE GOOD –

The opening scene of Prometheus sharpening his blades, Artemis walking up on him, everything revealed in the reflections of the puddles of water and knives was dope.

Yay! The flashbacks actually meant something this week. They added to the story instead of providing needless examples from the past of things playing out in the future (considering the results were often the same). Another feather in their cap was the flashbacks were to Oliver: Year One, as opposed to the One Night in Bratva tales we were saddled with in episodes 1-8.

This doesn't mean there weren't subtle nods to Flashbackistan. Prometheus does a move that Oliver was taught in Russia. And Reporter Girlfriend Susan likes herself some Russian vodka (remember she found out about Oliver's past awhile ago).

In giving up the tapes of his nightlife activities to Paul, Curtis admits that Mister Terrific has been Brother Pathetic with those hands.

THE BAD –

Let me get this straight. Evelyn – unable to work with Oliver after finding out about his murderous origins (?) – switches sides to run with Prometheus, ignoring the blue blood on his hands. Then, as soon as she gives up the Arrow tapes, she and Prometheus set up a confrontation with said Team Arrow so that they can tell the team about her double-cross. After which, Aretmis is gone from the show. Really?

Prometheus wants to "make Green Arrow wish that he was dead" so he kills police officers for his macabre display but chooses to infect Curtis with a disease that is removed from his body over a commercial break. He spends the episode recovering from the butt-whuppin' his heart took more than anything Prometheus did.

Detective Boyfriend Billy uncovers a picture of a black baby in a locked box in a desk at Factory Claybourne and sends a pic of the pic to Felicity before he's captured. Unless he suspects a child porn element, I don't see the urgency in sending out the picture. It's suspicious, true. But his actions didn't feel real, to me.

I think part of the reason it didn't feel right is because I think this –Felicity deduces that this is a pic of an illegitimate son of the deceased Claybourne who could be of age to be running around throwing stars into folks' necks – is a backhand way to explain what seems like actor Michael Dorn's voice coming from Prometheus' body. Maybe it isn't our man Worf *after all but it sounds awfully close. And I'm betting the the optics of another masked villain being voiced by a black actor but revealed to be a white actor in the suit (see The Flash's Reverse Flash and Tony Todd) weren't that appealing to The CW. Face it – it makes no sense plot wise. How would Prometheus know Billy was going to be skulking about when he's so fixated on Oliver? If he doesn't catch Billy in the act, who was going to serve as his sacrificial lamb in the Hall of Mirrors, assuming that was a scheme all the while?

THE UGLY –

Laurel Lance? When Felicity said "people who are dead turn out to be secretly alive pretty much every Wednesday," I should've checked out then and there. Unless this is a dream (ugh!), a clone (ouch!) or a Barry Allen-flavored time apparition (ugh, but it'll pass), I'm calling shenanigans.

THE VERDICT –

Episode 509 What We Leave Behind – left a stain on a relatively decent season. Score – C minus. Season 5 grade: B-ish.