Will our summer of nostalgia ever end? The hot months of 2007 have been shot through with observances of the 40th anniversary of “Sgt. Pepper’s Lonely Hearts Club Band” and the summer of love as well as the 30th year since the 1977 summer of punk and the death of Elvis Presley. Didn’t anything memorable occur in the summer of 1987? Perhaps historians in 2017 will walk like an Egyptian back to that time and uncover something interesting.

But the summer’s most dominant nostalgic theme has to be the marking (and marketing) of the 10th year since the death of Princess Diana, an event that now inspires its own conspiracy theories.

According to the network, “The Murder of Princess Diana” (8 p.m. today and 5 p.m. Sunday, Lifetime) is a fictionalized account of a book based on the notion that Diana was silenced by government big shots.

Jennifer Morrison (“House”) stars as Rachel, an American journalist following Diana’s efforts to outlaw landmines. A serious reporter, she’s horrified by the tabloid buzz around the princess, but she believes Diana can make a difference.

When Rachel arrives in Paris on that fateful August day, she sees the Ritz Hotel crawling with spies. What gives? Like a spunky Brenda Starr, Rachel hops on a photographer’s motorcycle as Diana and Dodi take their last limo ride. She’s an eyewitness to history. Within moments of the crash, Rachel smells a cover-up. Evidence is suppressed. Witnesses vanish, or worse. Rachel and her former paramour Gregori (Thomas Sylvestre), a French police officer, find official doors shut in their faces. Then things get really dangerous.

After a slow build, “Murder” unfolds like a tidy little political thriller. But what is fact and what is conjecture?

Rachel’s actions as a journalist circa 1997 just don’t make any sense. Despite her status as a key witness, she covers the story the old-fashioned way – s-l-o-w-l-y – ignoring the 24-hour media crush that was so much a part of Diana’s life and death. If Rachel knows so much and has so many contacts, why does she act so furtively? Why doesn’t she appear on cable news and expose the story to the world?

And the grand, overarching conspiracy theme that Diana was snuffed because she was on the verge of becoming a thorn in the side to the powerful seems a bit too much. After all, if embarrassing the crown were a capital crime, how does Fergie survive?

Related specials include documentaries “Diana: In the Name of Love” (7 p.m. Sunday, BBC America); “The Art of Diana” (8 p.m. Sunday, BBC America); and “Diana’s Last Day” (7 p.m. Sunday, E!).

¢ Much like “The Murder of Diana,” the popularity of “Army Wives” (9 p.m. Sunday, Lifetime) depends on the combination of real-life fears and good old-fashioned soap opera suds. The season finale is crammed with divorce ultimatums, pregnancy scares and hugs.

¢ “Countdown with Keith Olbermann” (6 p.m. Sunday, NBC) gets network exposure and sets up the former ESPN star’s return to sports coverage for the first time in years. Olbermann will be part of the “Sunday Night Football” (7 p.m. Sunday, NBC) team, along with Bob Costas, Cris Collinsworth, Jerome Bettis and Tiki Barber.

Tonight’s highlights

Note: Schedules may vary due to local sports coverage.

• The final four compete on “America’s Got Talent” (7 p.m., NBC).
• A familiar sitcom star tries out standup material on “Bob Saget: That Ain’t Right” (9 p.m., HBO).

Sunday’s highlights

• The Steelers host the Eagles on “Sunday Night Football” (7 p.m., NBC).
• Hilary Duff and Nick Cannon host Teen Choice 2007 (7 p.m., Fox).
• Bill tries a new approach on “Big Love” (8 p.m., HBO).