Big Brother 12 (8pm, CBS) - The twelfth installment of "Big Brother" begins tonight. The  house guests are introduced and we learn that one of them is a saboteur whose sole mission is to wreak havoc in the house. So it's sort of a "Big Brother" meets "The Mole" this time around. Who will it be?

Rookie Blue (9pm, ABC) - The police department throws a "Fite Night" charity event, and Andy faces a tough decision regarding a domestic violence victim.

Boston Med (10pm, ABC) - A neurosurgeon prepares for a risky surgery removing a cancerous tumor from a man's sinus cavity. Also, a first year surgery resident attempts his first appendectomy and discusses dating prospects with a colleague.

Bethenny's Getting Married? (10pm, Bravo) - This is it: wedding day.

Ace of Cakes (10pm, Food) - Duff builds his tallest cake ever, modeled after an Egyptian pharaoh, but transporting it turns out to be a huge problem.

The Ultimate Merger (10pm, TV One) - Chef G. Garvin helps the bachelors with a cooking challenge, and ends up clashing with one of them. I'm still trying to figure out why any of these men want to date Omarosa to start with.