It is sincere without being soppy, a balancing act most shows fall off. Keep an eye on the scorpion; the episode certainly does. There is a generous helping of flashbacks, served cold. Long-time viewers get a payoff: "How do you do? I'm Leslie Higgins." is no longer a mystery. The line of the week goes to "Did you know oysters come from the sea?", which deserves to be embroidered on a cushion. Pleasant company for half an hour.