The Office began last season with four hour-long episodes, none of which popped the way the series does at its best. It's not that the show can't work in one-hour increments, as evidenced by the season's brilliant finale a few months later.

The Office began last season with four hour-long episodes, none of which popped the way the series does at its best. It's not that the show can't work in one-hour increments, as evidenced by the season's brilliant finale a few months later. (Retarded Kevin remains one of the all-time best Office gags.)

No, those first four hours simply weren't as smart, funny or moving as they should have been. Most of the right pieces were there, but they weren't properly assembled.

That isn't a problem as the show's fifth season gets underway. The momentum that began in last season's string of strong post-strike episodes continued with last Thursday's season premiere, part of another set of four hour-long installments.

"Weight Loss" had a little bit of everything. While catching us up on every loose end from that great finale, it kept us engaged, inspired countless guffaws and delivered some of the most emotionally satisfying moments in Office history - and that's saying something.

"The Office"

9 p.m. Thursdays, NBC

Grade: A

Like all the best Office episodes, this one tugged heartstrings without devolving into soap-opera territory by diffusing every heartfelt gesture - Andy's (Ed Helms) speech to Angela (Angela Kinsey), Michael's (Steve Carell) intervention with Kelly (Mindy Kaling) - with hilariously inappropriate hijinks.

The one exception to that rule was Jim (John Krasinski) and Pam's (Jenna Fischer) highly significant encounter in the rain, a moment of pure sentimentality earned by years of setup.