Busy Philipps appears on the second season premiere of “The Mortified Sessions” (9 p.m., Sundance). She played one of the most memorable characters on television’s most-beloved canceled series, “Freaks and Geeks.” She was Kim Kelly, a pretty but tough girl with a vulnerable side that made her all the more endearing.

Like the rest of the ensemble cast of “Freaks,” Philipps was a virtual unknown at the time. And like her cast mates — including James Franco, Linda Cardellini, Seth Rogen and Jason Segel — she has been anything but anonymous since. Phillips can now be seen in “Cougar Town” (moving soon to TBS).

For the uninitiated, “Mortified” host Dave Nadelberg sits down with well-known guests and their scrapbooks and memorabilia from childhood and adolescence. He asks them about youthful hopes and dreams, perceptions of the world and themselves, and when, if ever, they knew they were destined for their current careers.

By keeping the focus on childhood embarrassments and mishaps, “Mortified” dwells in the awkward democracy of junior high school, a place where even those future celebrities felt miserable.

• For reasons of decorum and security, presidential appearances and state functions can seem choreographed and scripted. “Secret Service Files: Protecting the President” (8 p.m., National Geographic) shows how scary things can get when state events get out of hand. Agents recall the chaos that threatened President Bill Clinton’s life when he attended a state funeral in Morocco, surrounded by 2 million emotionally distraught bystanders. Or the time that a riot broke out just before an address by President George H.W. Bush in Panama. And the time that a live grenade was thrown in the direction of George W. Bush when he visited Tbilisi, Georgia, in 2005.

Tonight’s season premieres

• A honeymoon on hold on “90210” (7 p.m., CW).

• Serena among grown-ups on “Gossip Girl” (8 p.m., CW).

Tonight’s other highlights

• An exotic animal figures in a gruesome case on “Bones” (7 p.m., Fox).

• A new case is a familiar face to Grace on “The Mob Doctor” (8 p.m., Fox).

• An apparent overdose on “Major Crimes” (8 p.m., TNT).

• Nate keeps track of the group’s movements on “Revolution” (9 p.m., NBC).

• “Anthony Bourdain: No Reservations” (8 p.m., Travel) takes a look at the seven deadly sins.