"Commander In Chief" (9 p.m., ABC): Things are heating up for Mackenzie Allen, the country's first

"Commander In Chief" (9 p.m., ABC): Things are heating up for Mackenzie Allen, the country's first woman president. She's forced to face her first national crisis when nine DEA agents are killed in Latin America. No doubt she'll have plenty of skeptics questioning her every move.
"Supernatural" (9 p.m., The WB): The scary new series continues to dig up spine-tingling stories. In tonight's episode, when some mischievous teenagers unwittingly summon the violent spirit of Bloody Mary, Sam and Dean must find some way to destroy her before she can kill again.
"Martha Inc: The Story of Martha Stewart" (7 p.m., Lifetime): Now that super homemaker Martha Stewart is well on her way to rebuilding her reputation, Lifetime reminds us of when it was in tatters with this fairly trashy TV movie about her life. Cybill Shepherd's over-the-top portrayal of Stewart's rise to power is only bested by "Martha Behind Bars," in which Shepherd also stars and which airs immediately after.
"Nova" (8 p.m., PBS): While most people know of Einstein's E=mc2, few know what is actually means. Tonight, on the 100th anniversary of said equation, host John Lithgow guides us through the famous formula and how it affects our daily lives. Top university scientists and physicists are also interviewed.