Table:
text: List of Out of the Unknown episodes
Series 4
Series 4
Episode Title Story Adapted_by Director Airdate Exists_
401 “Taste of Evil” John Wiles n/a Michael Ferguson 21 April 1971 No
402 “To Lay A Ghost” Michael J. Bird n/a Ken Hannam 28 April 1971 Yes
403 “This Body Is Mine” John Tully n/a Eric Hills 5 May 1971 Yes
404 “Deathday” Angus Hall Brian Hayles Raymond Menmuir 12 May 1971 Yes
405 “The Sons and Daughters of Tomorrow” Edward Boyd n/a Gerald Blake 19 May 1971 No
406 “Welcome Home” Moris Farhi n/a Eric Hills 26 May 1971 Yes
407 “The Last Witness” Martin Worth n/a Michael Ferguson 2 June 1971 No

Question: From Out of the Unknown episodes list, what was the title of the episode where Martin Worth wrote the story for series 4?