If you don’t count his fun cameo in the epic Arrowverse crossover “Crisis from Earth-X” back in November, then it’s been years since anyone has seen Colin Donnell’s Tommy Merlyn alive in the DC TV series Arrow. But on Twitter, Donnell is teasing his shocking return, and it’s going to be pretty weird.

On Thursday, Donnell shared a video of himself on Twitter, wearing series star Stephen Amell’s Green Arrow costume on the set of Arrow Season 6. Without saying a word, Donnell reveals himself, sitting in Amell’s chair. No one says a word, though when Donnell de-hoods, a voice can be heard mutterring, “Hmm.”

Donnell captioned the video, “Wait for it…” which Amell later retweeted with his own tweet, “Open your eyes, Tommy,” the last words Oliver Queen told his best friend before he died in the Season 1 finale back in 2013.

Donnell has already confirmed he is returning to Arrow in an interview with TVLine earlier this month (and before that, back in March, Amell teased his return with a photo of his set chair on social media). But the circumstances of Tommy’s return remain unknown, and wearing the Green Arrow costume can’t just be behind the scenes shenanigans. (Unless it is.) Could Tommy be suiting up as the Green Arrow, or under a different vigilante identity?

Though he didn’t live long enough to become a superhero or villain, “Tommy Merlyn” was the son of series antagonist Malcolm Merlyn, a.k.a. the Dark Archer (John Barrowman). Tommy died in the Season 1 finale, where he was crushed under the rubble of his father’s grand plan to implode large swaths of Starling City in order to let the city rebuild.

Later in Season 5, it was a popular fan theory that Tommy would return as the masked villain Prometheus. Prometheus wound up being a new character, Adrian Chase (played by Josh Segarra), but the crossover from November homaged the theory, with Donnell back for a brief appearance as the Earth-X version of Tommy, who took up the Prometheus identity. On Twitter, Amell revealed Donnell shot his scene in secret and within one day, before returning to the set of NBC’s Chicago Med where he’s been a series regular since 2015.

Arrow Colin Donnell Tommy Merlyn
Colin Donnell, as he appeared in the very first season of 'Arrow' between 2012 to 2013.

Regardless of how long Donnell will be back in Arrow, he will be the second major principal actor to make any kind of comeback. Colton Haynes, who played Roy Harper in Seasons 2 and 3 (plus a guest appearance in Season 4), returned for a multi-episode arc a few weeks ago. Around the same time, news broke that Haynes would return as a series regular starting this fall in Season 7.


Arrow* airs Thursdays at 9 p.m. Eastern on The CW.