This second half of a two-hour movie opens with producer Philip Saltzman's favorite scene in the whole series: Barnaby, who arrived too late to save a key witness from being stabbed to death (by a matter of seconds) forgoes his usual milk drinking and has a belt of the hard stuff in his office while staring hard at the glass.
Series regular Lee Meriwether and guest stars Sherry Jackson and Marj Dusay all appeared on separate episodes of Star Trek (The Original Series).