The ninth season of Two and a Half Men premiered on CBS on September 19, 2011, with Ashton Kutcher joining the cast as Walden Schmidt. This season is the first without the show's star Charlie Sheen, as well as the first to feature a retooled plot, marking a major change in the series by focusing on Alan moving on with his life after the death of Charlie with help from his new best friend and housemate, Walden, a dot-com billionaire who is in the process of being divorced by his wife. The trio bond and form a surrogate family unit. This was the last season to air on Mondays.