The CW have released the official episode summary for May 7's penultimate episode of Arrow's second season -- and Season One big bad Malcolm Merlyn (John Barrowman) will be back. It's no great surprise, since Barrowman was recently spotted snapping selfies with co-star Willa Holland (Thea Queen), who plays his biological daughter on the show (although they've never known this while on screen together). And that's not even the biggest (apparent) spoiler in the episode, which we'll leave undiscussed up here and allow it to play through the summary below, in case anyone wants to bail out now. The episode, named after a track on the Bruce Springsteen album Darkness on the Edge of Town (just like the second-to-last episode of Season One), seems a bit more intimate than it has been in a while, unless there are additional guest stars not yet announced or listed in the synopsis below. Besides Merlyn, there aren't any listed guest stars, and it seems as though the second-to-last episode is very much just Slade and Oliver throwing down while the rest of Team Arrow is largely off camera setting up for the finale. "Streets of Fire" will air on May 7 at 8 p.m. EST on The CW. You can see the official text below. ARROW "Streets of Fire" — (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV) MALCOLM MERLYN RETURNS — Oliver (Stephen Amell) rallies his team as Slade's (Manu Bennett) soldiers attack the city. Felicity (Emily Bett Rickards) gets a call from S.T.A.R. Labs with game-changing news and Thea (Willa Holland) comes face-to-face with her father – Malcolm Merlyn (guest star John Barrowman). Nick Copus directed the episode written by Jake Coburn & Ben Sokolowski (#222).