The 100th episode of Arrow has now come and gone, having aired on The CW last night. The November 30th installment had the mutual challenge of being a milestone as well as part of The CW's heroes-vs.-aliens "Invasion!" crossover.

Speaking to press earlier this week, Arrow Executive Producer Marc Guggenheim talked a bit about what it was like to juggle it all together.

"That was the challenge was just how much to service the 100th episode-ness, and how much to service the crossover," Guggenheim said about the balancing act. "I think it’s pretty obvious that we chose to go 100th episode, but it was totally a challenge," he said, adding that it was the idea of Greg Berlanti to have the five Arrow characters in the "Dominator matrix" - lowercase "M" - as a way to have their cake and eat it too, to look to Arrow's past and faces we once knew while at the same time serving as a satisfying chapter of the crossover. Guggenheim is also aware that we've seen similar stories in the "Arrowverse" before.

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Image via The CW

"We make a reference actually at the end of the Legends of Tomorrow episode of the crossover, that this was sort of Oliver’s version of Flashpoint and it’s a little bit the version of Oliver’s version of 'The Girl Who has Everything' from last year’s Supergirl," he acknowledged.

"There’s a reason why these stories are iconic or familiar tropes even in comic books. It’s because when you show the protagonist the path not taken and you basically put them in the situation where they can choose to stay on that path or go back to their life with all of its ugly aspects and challenges, and they choose the selfless choice of returning to that ugly past, it makes your character stronger because, it’s like I said earlier, it forced Oliver to double down on his mission and commit to this life with all of its losses and failures and challenges."

That new sense of purpose for Oliver will come to the forefront in the December 7th midseason finale. "The events of 508, basically, forced him to emotionally double down on his mission, so he goes into 509 with a new sense of purpose, and I would say, also, a reaffirmation of his bond with Thea, because they basically chose each other in 508," Guggenheim confirmed. "That carries through the midseason finale and, obviously, sets up things beyond it." Also not off the table? Discussion of Flashpoint and its affects on the Arrow cast, now that that subject is out in the open.

"They deal with some of the ramifications, I think in some humorous ways, actually," Guggenheim said.

One recurring storyline not featured in the 100th episode will feature in the upcoming winter finale, and that's the big reveal about Evelyn Sharp/Artemis (Madison McLaughlin) that the show dropped a few weeks back. "I will say, you will get a payoff to 507’s cliffhanger with respect to Evelyn big time in 509," the producer promised.

Arrow airs Wednesdays at 8 p.m. on The CW. The midseason finale, "What We Leave Behind," airs on December 7th.

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Image via The CW
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Image via The CW
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Image via The CW