Doo" (20 September 1969) was the only one to feature  Nichols theme for both opening and closing credits. The following  episodes used the Mook/Raleigh theme for the opening credits and the  Nichols instrumental theme under the closing credits sequence:  episode 1.3 "Hassle in the Castle" (27 September 1969, episode 1.13  "Which Witch is Which?" (6 December 1969), and episode 1.16 "A Night  of Fright is No Delight" (10 January 1970). All other episodes used  Mook and Raleighs theme for both opening and closing credits.