Stab 5 finds the cast of the amateur fan film Stab 4: Fresh Blood under attack, again playing on the reality-within-a-reality of the Stab films and taking it to the next level.
After two cast members of Stab 4 are brutally murdered, the town of Manchester, New Hampshire is on edge as rumors of a Ghostface mask wearing psycho quickly make their way around town. Joshua Dudley, writer and director of Stab 4, and his producer, Rachel Arnold, are busily working on their production of Stab 5 when they receive the news. Deciding the film's production is worth more to them than the safety of their cast, production rolls on.
Who would want to kill the cast of Stab 4? Is the killer following the same rules we all know and love? But the most important question on everyone's mind: who's next?