The focus lately for the CW has been the Heroes vs Aliens 4-series crossover, but what's not getting much attention is that the following week will be the midseason finales. As the shows will be off the air for a little over a month, Supergirl returning first January 16th, the series usually like to have a big cliffhanger ending to make people thinking about the show in it's absence. So what might happen?

Supergirl is the one we know the least about. No synopsis for Supergirl Lives has been released, but we know the title is an homage to the Superman film that episode director Kevin Smith wrote. Smith has shared some photos from the set and got his daughter Harley Quinn Smith cast in the episode. Smith has said it's the biggest thing he's ever directed and it's filled with 'deep-cuts' characters from some of his favorite DC stories. Not much to go on there.

The Flash is leaving his world again and heading to Earth-3 to go see Jay Garrick in The Present. He's having a rough time trying to deal with Savitar and Doctor Alchemy, so Barry Allen jumps through a portal to go see the man that looks a lot like his father. We've already seen what the writers and effects people could come up with for Earth-2, what will Earth-3 be like and how will it differ from the Earth Barry knows?

Arrow appears to be the series that is staying hard on it's main storyline for the season in an episode called What We Leave Behind. Curtis Holt is attacked by Prometheus and Oliver Queen realizes that the villain knows all of the teams secret identities. We know how, because Evelyn Sharp is working with Prometheus… but it looks like Green Arrow might figure it out. And in a side note, we may be flying down the path to the return of Laurel Lance. She shows up in the 100th episode this week, but an episode marked for January called Second Chances has "The team feels strange as Laurel returns" as the description. There's been some speculation that Flashpoint would undo Black Canary's death… but what if we saw what really did it, White Canary telling Damian Darhk that his plans fail in the future and Darhk going with Eobard Thawne instead to change his destiny. That could erase all of season 4.

And finally, DC's Legends of Tomorrow is going out with a bang by bringing together the Legion of Doom. We know that Malcolm Merlyn joins the team in an episode called The Chicago Way… an homage to the Kevin Kostner / Sean Connery Untouchables film maybe? This is also the episode we expect the return of Wentworth Miller as Captain Cold. The question becomes when do they join the Legion of Doom? Thawne can pull them from anywhere in time. He could've grabbed Cold just before the bomb went off in the second to last episode of Legends season 1 or he could be from some other point in time when he didn't start becoming a hero. And will it be current Merlyn with the missing hand or an younger Merlyn who hasn't started the Undertaking yet and has no familiar ties to Thea Queen that he knows of. Also, we know that the Legion is Reverse-Flash, Damian Darhk, Malcolm Merlyn and Captain Cold… but is that all that will be part of the team? Seems like their may be room for one or two more.

And for anyone wondering why Rip Hunter hasn't been around since the season premiere… it's not because he wanted too much money, or didn't like the scripts or any of the other speculation that has been bouncing around on-line. It's because of David Tennant. Or rather because of the series he's doing with David Tennant on the BBC. Arthur Darvill had a scheduling conflict with the third season of Broadchurch that he was contractually obligated to do. As much as he'd like to do both, Broadchurch is filmed in England while Legends is in Canada and the Waverider isn't real.