"Arrow's" 100th episode is going to be a very busy affair. It lands right in the middle of a crossover that mixes in characters from "Supergirl," "The Flash" and "Legends of Tomorrow."

That leaves the show in an interesting position as it also needs to be a time of reflection that pays tribute to the 99 episodes that came before it -- as well as something special for fans that have been there since the beginning.

"We did have a very unique challenge this season in that the crossover fell on the 100th," executive producer Wendy Mericle admits at the 100th episode celebration. Everybody involved believes they pulled off the seemingly impossible, though.

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"We knew that we were going to have to [deal], in some ways, with these new elements that were never in the DNA of the show... Our goal was to do the 100th and make it a love letter very much to that first season -- before there were superpowers, before there were metahumans, before there were aliens, for example," she explains. "I have to say, I think we found this great way of doing it that honors all the other shows, but also is very much an homage our first season and to the Queen family in particular."

Given the news that Susanna Thompson will be returning for the episode as the long-dead Moira Queen, honoring that family is a particularly interesting proposition. It's unclear exactly how Moira will reappear in Star City, though chances are it will be an emotional moment for both Oliver (Stephen Amell) and Thea (Willa Holland).

It will be interesting to see how the show's writers have managed to pay proper tribute to the show while also working within the confines of the crossover. "It has some incredibly iconic moments," executive producer Marc Guggenheim said previously. "It is a love letter to the show."

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In a way, that's what a lot of Season 5 has been like. After going all over the map in recent seasons -- including pitting an archer against someone with actual magical powers -- getting back to basics is refreshing. If the 100th episode is the pinnacle of the homage "Arrow" has been paying to the first seasons, it may end up becoming exactly what fans have been dying for.

Posted by:Chris E. Hayner

Chris E. Hayner is equal parts nerd, crazy person and coffee. He watches too much TV, knows more about pro wrestling than you do and remembers every single show from the TGIF lineup. You may have seen him as a pro-shark protester in "Sharknado 3." His eventual memoir will be called "You're Wrong, Here's Why..." TV words to live by: "I'm a firm believer that sometimes it's right to do the wrong thing."