six in which he portrayed the eighth Lieutenant Governor of Ontario, Oliver Mowat. Thomas Howes made a guest appearance as Winston Churchill, who asked Murdoch's help when he was accused of murder. Georgina Reilly (Dr. Emily Grace) was promoted to series regular for the sixth season. Season 7 (2013-14) On April 2, 2013, CBC renewed Murdoch Mysteries for a seventh season, to consist of an extended order of 18 episodes instead of the usual 13. The seventh season had its premiere on September 30, 2013. Season 8 (2014-15) On April 4, 2014, CBC renewed Murdoch Mysteries for an eighth season. Season 9 (2015-16) On March 4, 2015, it was announced that CBC had renewed Murdoch Mysteries for a ninth season. On May 25, 2015, it was announced that William Shatner would be guest starring as author Mark Twain. Season 9 will see guest appearances of Lucy Maud Montgomery, Prime Minister Wilfrid Laurier and Mouna Traoré as Rebecca James, a young protegee whom Julia takes under her wing. Season 10 (2016-17) On March 31, 2016, CBC announced the tenth season of Murdoch Mysteries, ten days after the ninth-season finale. Season 11 (2017-18) On March 13, 2017, CBC renewed the show for an eleventh season consisting of 18 episodes and a third two-hour Christmas special. This season saw the return of Alexander Graham Bell and Theodore Roosevelt. Helen Keller, Anne Sullivan and Dr. William Osler made guest appearances as well. Dylan Neal reprised his role as Jasper Linney, Murdoch's half brother, during the Christmas special, last seen in the season two finale. Mouna Traoré, who played Rebecca James, left the show in episode two, with a guest appearance in episode seventeen. Shanice Banton joined the cast in episode four, in a recurring role, as Violet Hart, a medical student and Julia's new morgue assistant. Season 12 (2018-19) Unlike seasons nine through eleven, the twelfth season of Murdoch Mysteries did not include a Christmas movie, opting instead for an "out of the box" Halloween episode. Former Canadian Olympic figure skater Elvis Stojko guest starred in episode 13 as ex-con Sam Marshal, who Murdoch suspects of murder. The episode also saw the return of, Dmitry Chepovetsky as Nikola Tesla, whose last appearance was nine years ago in season 3, episode 13. Colin Mochrie reprises his role from last season as Ralph Fellows and Patrick McKenna returned as Inspector Hamish Slorach, last seen in season