The four series (1989-95) demonstrate diminishing returns. The first couple are excellent through and through, although the second is perhaps less experimental. The third is noticeably weaker and somewhat under-written, although the old magic bobs up periodically. The final series was worryingly poor, and its reviews were a contributing factor to Fry’s departure to Belgium. As if to hammer the point home, the pilot (1986) is probably the strongest show of all. Anyway, we only have one entry...