With filming on the second episode of The Flash underway, we have yet another exciting new addition to its cast. After being spotted on the set of the Arrow spin-off, Iron Man 3 actor William Sadler has confirmed (via Flash TV News) that he will play Simon Stagg in “Fastest Man Alive.” Stagg is the CEO of Stagg Industries, which was previously referenced on Arrow. In the comics, he played a key role in Rex Mason’s transformation into Metamorpho. Arrow has also featured a couple of Metamorpho Chemical Easter eggs. It’s unknown what role Stagg will have in The Flash, but could we be seeing the Metamorpho story play out in the series? The spin-off opens the door to metahumans, so it’s not out of the question. Stay tuned for more news as we have it. The Flash premieres on October 7th on The CW.