Ep 5. The Understudy

In "The Understudy," the fifth episode of "Inside No. 9" season 1, viewers are taken behind the scenes of a theatrical production. The episode centers around the play "Macbeth," and the understudy for the lead role, Simon (played by Steve Pemberton).

Simon is eager for his chance to shine, as he has been the understudy for months and is feeling unappreciated by the rest of the cast and crew. When the lead actor is suddenly unable to perform, Simon finally gets his chance to take the stage. However, things quickly take a dark turn as Simon doesn't seem to be able to differentiate between reality and the play.

As the production spirals out of control, the rest of the cast and crew are forced to deal with the consequences of Simon's obsession with the play. The tension builds to a shocking conclusion that is sure to leave viewers on the edge of their seat.

Throughout the episode, viewers are treated to some brilliant performances from the cast, which includes some familiar faces from British television such as Reece Shearsmith, Anna Chancellor, and Katherine Parkinson. The episode also features some impressive set design and lighting, which add to the ominous and claustrophobic atmosphere of the theater.

Overall, "The Understudy" is a suspenseful and entertaining episode of "Inside No. 9" that will keep viewers guessing until the very end. With its clever writing and strong performances, it is a standout installment in an already impressive season.