Episode #18.5 - [s18e5]

Season 18, Episode 5, titled "The Serpent's Cove," follows a veteran and a cattle rancher trying to survive 21 days in the Philippine jungle.

If you are looking for a show specifically using the notation (often used for mid-season recaps or specials), it likely refers to one of the following:

Episode 18.5, titled "All of This," is a recap episode that summarizes the events of the series up to that point. Community consensus on Reddit generally suggests it is skippable if you are binge-watching. [S18E5] Episode #18.5

Jeremy Clarkson and James May explore the history of Saab, highlighting its engineering eccentricities, such as the ignition being located between the seats and the company's roots in aviation.

Matt Smith, then the lead in Doctor Who , joins the show to set a lap time on the Top Gear track. Season 18, Episode 5, titled "The Serpent's Cove,"

In Season 18 (projected/upcoming), Episode 5 involves a multi-week challenge where contestants must form alliances and rank each other.

Episode 18.5, "Recollection," is similarly a compilation episode summarizing the first half of the Alicization arc. Jeremy Clarkson and James May explore the history

Richard Hammond conducts a spectacular race in the Alps, pitting a rally-spec Skoda Fabia S2000 against Swiss stuntman Yves Rossy, who uses a rocket-powered wing to fly through the mountains.