Guest Stars Gretchen Mol as Gillian Darmody Greg Antonacci as Johnny Torrio Erik Weiner as Agent Eric Sebso Tom Aldredge as Ethan Thompson Dana Ivey as Mrs. McGarry Emily Meade as Pearl Co Starring Connor Noon as Tommy Darmody Brady Noon as Tommy Darmody Josie Gallina as Emily Schroeder Lucy Gallina as Emily Schroeder Declan McTigue as Teddy Schroeder Rory McTigue as Teddy Schroeder Victor Verhaeghe as Damien Fleming Robert Clohessy as Alderman Jim Neary Nisi Sturgis as June Thompson William Hill as Alderman George O'Neill Edward McGinty as Alderman Al Boyd Pearce Bunting as Bill McCoy David Aaron Baker as Bill Fallon John Rue as Mayor Harry Bacharach Nic Novicki as Carl Heely Steven L. Barron as Vocal Reporter Susan Varon as Madam Regina Faith Sandberg as Kitty Susan Blommaert as Irene Davis Lynne Valley as Temperance Singer Mark Povinelli as Kevin Kiley Cezary Skarzynski as Boxer #2 Erin Mae Miller as Temperance Singer Fran Lieu as Temperance Singer John Keating as Celt #4 Jack O'Connell as Celt #3 Christopher J. Quinn as Reporter #2 Judson Jones as John #1 Sean Allison as Boxer #1 Raymond McAnally as Workman #1 Nicole Lackey as Temperance Singer Mikey Post as Mike Green Margot Jewers as Temperance Singer Laurence Lowry as Celt #2 Kenneth Cavett as Drunken Celt John Treacy Egan as Duncan O'Connor John Joseph Gallagher as Celt #1 Austin Jones as Waiter Martin Anna Stone as Bridget Walsh Edelen McWilliams as Bettyanne Mulhaney