They made a big mistake by not settling the Mama McGarrett plot at the end of Season 3. The whole Shelburn/Mama McGarrett storyline has been dragging this show down like an anchor for the past two seasons. Even Terry O'Quinn's character was annoying as fuck. After a strong 1st season, recurring storylines have not been this show's friend. With them moving to Fridays, they need to ditch these failed storylines for good.