The dead walk the earth this Sunday night -- and on PBS, no less.

It is a testament to the popularity of Inspector Morse, the British television character created 25 years ago by the novelist Colin Dexter, the producer Ted Childs and the actor John Thaw, that after he was killed off with great ceremony in 2000, it was thought necessary to bring him back. That exhumation has been accomplished with a prequel, ''Endeavour,'' which opens the new season of ''Masterpiece Mystery!''

Sunday night's episode, shown in Britain in January, was the pilot for a series that has been picked up by the ITV network for an additional four installments; presumably these will arrive on PBS in due course. Fans of the detective will already know that the title is Morse's given name, which he kept secret and which was revealed near the end of the original series's 33-episode run.

''Inspector Morse'' was distinctive for three reasons: Mr. Thaw's idiosyncratic, often unsympathetic performance; the testy relationship between his misanthropic, snobby, eternally disappointed Morse and Kevin Whately's earnest, proletarian Sergeant...