Despite being an important figure in the Queen family, Walter Steele (Colin Salmon) left Arrow in a season 2 episode and never returned. Though never billed as a series regular, Salmon had a major presence throughout the show’s first season as a former associate of Robert Queen and the current husband of Moira (Susanna Thompson).
Walter played a memorable role in the main storyline of season 1, which was Malcolm Merlyn’s plot to destroy the Glades. He became one of the first characters outside of Team Arrow to figure out that something nefarious was afoot and had a lot to do with Felicity (Emily Bett Rickards) joining the fold in a significant capacity. Following his divorce from Moira, he received a reduced role in season 2, with the character’s last appearance being in the season’s penultimate episode, which showed the aftermath of Moira’s death. Later seasons revealed that Walter had off-screen interactions with characters like Thea (Willa Holland) and Oliver (Stephen Amell), but he never again appeared in the flesh.
An official reason for his exit hasn’t been offered, but his appearances becoming less frequent in season 2 indicate that his importance to the show shrunk a bit once Arrow moved on from the Malcolm story and shifted its focus away from the Queens’ civilian lives. As for why he didn’t come back, comments from former Arrow showrunner Marc Guggenheim have confirmed that there was an interest in getting Salmon back on the show as Walter Steele [via ComicBook]. Apparently, multiple attempts were made over the years, with one being the series finale. Presumably, he would have been one of the Arrow characters to cameo at Oliver’s funeral, but the actor was shooting something else at the time. Based on Guggenheim’s remarks, it would seem that this obstacle is what prevented Salmon from returning at any other points as well.
Salmon’s acting credits do show that the actor has kept busy with roles in various movie and TV projects since leaving Arrow. In recent years, he’s been involved with Some Girls, Limitless, 24: Live Another Day, London Has Fallen, Mortal Engines, and more. When Arrow was approaching its end, Salmon was in a different DC show, Syfy’s Krypton. In the Superman prequel series, Salmon played General Zod, one of the most iconic DC Comics villains of all time.
Most season 1 and season 2 characters (even ones who died) were able to come back on various occasions, including Oliver’s funeral in the finale. Like Walter, Deathstroke (Manu Bennett) didn’t make it for the show’s sendoff, but he was at least able to return for a fun storyline in seasons 5 and 6. Walter, on the other hand, remained absent from Oliver’s life. It’s disappointing that no opportunity ever arrived for Salmon to return as Arrow’s Walter Steele, who stands out as the biggest character from the early seasons to never return in any form. If he had made an appearance, it would have provided yet another touching callback to season 1 and how it all started.