"Penny for Your Thoughts" is the 15th episode of the first season of Medium , airing on May 9, 2005, and featuring the debut of recurring villain Charles Walker. Allison DuBois tracks a malevolent spirit possessing modern individuals to commit murders, with the episode featuring a notable production cameo from actor Jake Weber. View cast and crew details at IMDb . "Medium" Penny for Your Thoughts (TV Episode 2005) - IMDb