The extent to which Holmes opened Clemens’s eyes about the head readers as frauds, served as his leading guide into the pseudo-science of phrenology, and provided a template for him to lampoon the head readers is addressed in this chapter. Three questions are asked. First, was Clemens familiar with Holmess writings? Second, did he meet Holmes? And third, is there evidence to suggest that Clemens “borrowed” some of Holmess ideas and humorous ways of presenting his thoughts about the head readers and their so-called science? Each of these questions is answered in the affirmative using the letters they exchanged, showing when they met, and by examining their writings. Most notable is how Mark Twain used the same two-column structure that Holmes had used in 1859 to present what the head reader was telling a client but really thinking. This chapter is particularly important because Holmes has not been recognized for having such an influence on Clemens/Twain. Nor had it been shown how Mark Twain borrowed rather freely from Holmes. Then again, scant little has been published on Clemens’s/Mark Twain’s forays into phrenology and there is nothing on Holmes and the head readers.