Season 1 Episode 21 The Undertaking Arrow Episode 21 "The Undertaking" Photos: Oliver Brawls It Out! 04.19.2013. @ 03:58 ShahbazMalik Official spoiler filled photos for Arrow, episode 21 "The Undertaking" have surfaced online, check them out below. image gallery View: thumbs list Source: CW The episode is set to air Wednesday, May 1st. Check out the official guide for more spoilers!