Television critic Mike Hughes offers his picks for tonight's must-see shows.

"RESCUE ME," 7 P.M., FX

In its second episode of the season, we're reminded just how good "Rescue Me" can be.

Last week's opener -- ending a 19-month gap, extended by the writers' strike -- was very good; this one is brilliant. It demonstrates a dazzling ability to leap between tragedy and comedy.

Denis Leary, the star and co-creator, has long monologs at both extremes. One has Tommy Gavin's constrained view on Sept. 11 memories; the other is a free-flowing look at the faults of ... well, everyone.

The Sept. 11 reflections also have moving moments from Lt. Shea (John Scurti), but then the humor returns.

Catch the self-centered Sheila (Callie Thorne) as she tries to be a Big Sister. Or Tommy at the hearing that could dump him on "Section 8" mental grounds. Or Tommy confronting his ex-wife's new lover.

That last character is played by Michael J. Fox. Two wonderful actors frolic wonderfully, as guys consumed by pride, foolishness and testosterone.

"NOVA: DOCTORS' DIARIES" CONCLUSION, 8 P.M., PBS

This ambitious documentary has traced seven people for 21 years, from their days at the Harvard Medical School.

Early on, one decided to be an anesthesiologist, so he could have regular hours and a family life. There may have been logic there; he's apparently the only one of the seven who has had a long marriage.

Several of the doctors have had divorces (one is on his fourth marriage) and setbacks. Still, there is a stirring sense of service here. Blessed with smarts and education, most of these people have spent all or some of their careers helping the poor.