* American Idol (8 pm/ET Fox)
There was no saving Grace. Last week our coterie of crooners rendered the country staples of the Grand Ole Opry, but it wasn't a grand ole time for soulful, telegenic Alexis Grace. The dirty little singer with the big talent was - shock of shocks - given the boot. Did America get it wrong? That's worthy of Idol chatter. But the show moves on anyway, and tonight we find the Top 10 performing the classic staples of Motown. And what would that genre be without a little Berry Gordy and Smokey Robinson? Both Motown luminaries are in the house tonight.
They Killed Sister Dorothy (8 pm/ET HBO2)
Sister Dorothy Stang forged many friendships during her three decades as a missionary in the Amazon, where she fought for the rights of farmers to survive amid a toxic climate of corporate deforestation. Unfortunately, the Ohio-born nun also made a lot of enemies, and her fight ended in 2005 when she was shot dead in the jungle. Martin Sheen narrates this 2008 documentary, which looks at Dorothy's work on behalf of the peasant population and covers the trial of the men who were charged with her murder.
* Lost (9 pm/ET ABC)
OK, all of our players are back on the same field, give or take 30 years. But where's Locke? And as Jack asked Sawyer last week: "Where do we go from here?" Tonight we can expect to learn more about how Ben became the man he is in 2007 (the present in Lost) by seeing more of him as a boy (Sterling Beaumon) in 1977. But Sayid is our star. We'll learn more about his past, and he has a eureka moment. "Now," he says, "I know exactly why I'm here."
* The Tonight Show with Jay Leno (11:35 pm/ET NBC)
Prince kicks off a lengthy stay on the Tonight Show, where he performs tonight and again on Thursday and Friday. This three-day event nicely mirrors his upcoming three-CD Lotusflow3r release, which contains his new albums, Lotusflow3r and MPLSound, and Bria Valente's debut album, Elixir. Halle Berry and Frank Caliendo are also scheduled to appear on the show.
* Great Performances (8 pm/ET PBS (check local listings))
To quote the Bard: "How sharper than a serpent's tooth it is to have a thankless child." That sentiment, shared by many parents, sums up one of Shakespeare's greatest plays, King Lear, performed here by the Royal Shakespeare Company. It tells the story of a monarch (Ian McKellen) whose life is upended after he deigns to split his kingdom between the two daughters who fawned over him while disinheriting the third (Romola Garai), who dared express her true feelings for him.