It's difficult to say, given the show's somewhat more grounded and real-world feel than its sister series The Flash. But the name of the series' fiftieth episode -- which starts filming today -- is "The Magician."
The episode will be directed by John Behring, who has tackled a number of fan-favorite episodes, including last year's midseason and season finales and the game-changing season one episode "The Odyssey."
The fourth episode of the new season, "The Magician" was co-written by Executive Producer Marc Guggenheim, whose tweet revealed the information reported here, and Wendy Mericle, who wrote a number of Arrow episodes in the past including last year's penultimate episode "Darkness on the Edge of Town." She also wrote last year's Arrow: Blood Rush tie-in miniseries with Bose and has worked with Guggenheim on projects dating back as far as Jack and Bobby.
Seeing "The Magician" may immediately conjure up images of Zatara and Zatanna, but it seems more likely those characters will pop up on Constantine, given the relationship being built between Zatanna and John Constantine in the comics.
Of course, in some versions of the comics canon, Oliver Queen was inspired to take an interest in archery by an encounter with "Merlyn the Magician," who did trick archery, years before being stranded on the island where he would eventually become Green Arrow.
Arrow is filming now for a fall debut on October 8 on The CW. X-Men #18, Guggenheim's first issue as writer, is in stores today.