Bob Newhart's recent appearance on NCIS (episode: "Recruited") has the actor moving and speaking a little slower (he even needs help down a flight of stairs at one point), but it's entirely appropriate to the character, and besides, when ol' Bob delivers a clever line that ends on a smile, we realize he's still got it.
Newhart guests as Dr. Walter Magnus, the predecessor and mentor to the show's regular forensic coroner, Dr. Mallard (David McCallum).
As with his guest appearances on ER, Bob plays a character who (*major spoiler*) has an end-of-life health problem. It turns out that Dr. Magnus has dementia and has wandered away from home (instead of being estranged from his daughter, as he thinks, he is actually living with her). Is this all we can expect from any future prime-time appearances from the actor -- for him to play a senior grappling with distinctly senior problems? Hope not, but we Newhart fans will take anything we can get!
I don't mean for the above to sound so negative about what was a great opportunity for the comedic Newhart to give an emotionally moving performance (so perhaps I'm just bummed that, given Dr. Magnus' condition, we shouldn't expect a repeat appearance of the character).
The episode has some early dialogue about a "country inn" in Vermont (shades of NEWHART, anyone?), leading the viewer to think the story will perhaps be loaded with in-jokes. That's not the case, because when Newhart's character dials up a chinese take-out place, he doesn't even utter the words "moo goo gai pan" (fans of THE BOB NEWHART SHOW will know which famous bit I'm referencing!). --Mike Malloy