With HBO’s upcoming Watchmen series having added Jeremy Irons to its ranks earlier this week, now comes word that Tom Mison has also signed on for the show.

Courtesy of TVLine, the Sleepy Hollow favourite has landed an unknown but key role in the Damon Lindelof-created series. Similarly, Resurrection’s Frances Fisher and White Famous’ Jacob Ming-Trent have also joined the show in mystery roles.

In addition to Irons, this new trio join a cast that features The Leftovers’ Regina King, Django Unchained’s Don Johnson, Lincoln’s Tim Blake Nelson, An Officer and a Gentleman’s Louis Gossett Jr., The Brave’s Andrew Howard, and Rectify’s Adelaide Clemens. No details are known on just which characters any of these names are playing, although Regina King is believed to be the lead role of the series.

Watchmen began life back in 1986 as a twelve-issue miniseries from Alan Moore and Dave Gibbons, soon going on to become a hugely acclaimed classic and a tale regularly cited as one of the greatest comic book/graphic novel stories of all time. A big screen adaptation finally happened in 2009, with Zack Snyder directing a huge blockbuster starring the likes of Billy Crudup, Malin Akerman, Jackie Earle Haley, Matthew Goode, Patrick Wilson, Carla Gugino, and Jeffrey Dean Morgan.

This new series will be set in and around the Watchmen world that we know and love, yet will be a completely new and original story.

Expect more on Watchmen as it continues to develop.