[SPOILERS for those not caught up on The Flash season 2 ahead.]
The CW launched its superhero universe with Oliver Queen (Stephen Amell) in Arrow, then used the show as a launching pad to introduce Barry Allen (Grant Gustin) before he went on to star in his own spinoff, The Flash. This week, the two superheroes joined forces in the two-part, two-night crossover event that saw the Green Arrow and The Flash teaming up to save Hawkgirl and Hawkman from Vandal Savage - a precursor to their own spinoff Legends of Tomorrow that will debut on The CW in January.
Take a look at photos from the episode that show Wally as well as Joe's reaction:
The Flash hasn't revisited the storyline in quite a few episodes, taking time away to deal with Zoom and Vandal Savage, but earlier in season 2 Iris' mother Francine returned to Central City. During this visit it was revealed that Francine gave birth to a second child after leaving her family, presumed to be Wally, and now it appears Joe and Iris will officially meet him in "Running to Stand Still". Of course, because of the return of the rogues, it would seem the West family meeting will take a back seat to the larger action of the episode. But, the meeting will likely act as a kind of resolution to the Francine storyline earlier this season, and with Lonsdale joining The Flash as a series regular, there will be more time to explore his character - and perhaps his alter-ego as Kid Flash.
As for other new characters set to join The Flash, CB is reporting Marco Grazzini (Heroes Reborn) has joined the cast as Joey Montelone a.k.a. DC Comics villain Tar Pit. In the comics, Joe Monteleone was a small-time criminal in jail when he discovered he was a metahuman with the ability to astrally project his consciousness to inanimate objects, like a vat of hot tar. At one point in the comics, his consciousness became trapped in the tar, leaving his body in a coma in Iron Heights Prison. On The Flash, The CW revealed Tar Pit will be a vengeful metahuman that can transform into molten asphalt and against The Flash he will use "his powers to gain a tactical advantage over the Scarlet Speedster, who finds the ground literally shifting beneath his feet."
CB did not reveal what episode Grazzini will make his debut, just that it will be an upcoming episode, perhaps the midseason finale but more likely later on in season 2. Depending on whether Tar Pit will arrive in Central City from Earth-2 or be a victim of STAR Lab's particle accelerator explosion, the villain may hint that The Flash could return to dealing with metahumans from Earth-1. Many of the villains so far in season 2 have been tied to Zoom, before the evil speedster finally made an appearance himself, but it remains to be seen if Tar Pit will be connected to the main villain this year. Unfortunately, with The Flash going on its midseason break, we likely won't know more about Tar Pit until the show returns.
The Flash continues Tuesday with "Running to Stand Still" at 8pm on The CW.