What episode of family guy is then there where less?

Answer 1

"And Then There Were Fewer" episode 1 of season 9

The residents of Quahog are all invited to a mansion dinner party by James Woods, who states he has become a born-again Christian thanks to his new girlfriend Priscilla, and wishes to repent for all his wrongdoings. Early into the night, as Woods and Priscilla go to the kitchen, Quagmire's new companion, Stephanie, is mysteriously shot when she sits in Woods's seat, leading the guests to believe Woods intends to murder them all. Returning amidst accusations, Woods pleads ignorance before he too is murdered in front of the guests during a power outage. Trapped on the estate with no way of contacting anyone due to a thunderstorm, the guests realize that the killer is among them.

While the guests search for clues in discovering the killer's identity, Mort Goldman's wife, Muriel, disappears after it is discovered that she was being blackmailed by Woods, causing everyone to suspect her as the culprit. However, Muriel turns up dead soon after by being stabbed in the back, placing suspicion on Priscilla, who also disappeared during the commotion. Jillian's husband, Derek, leaves to find a cell phone signal so he can contact the police, but is soon murdered by the killer with one of Woods's Golden Globe Awards. The guests search everyone's rooms until they locate the bloodstained award and Priscilla's dead body in Tom Tucker's guest room. Tom is thus implicated as the killer and is chased and caught by Peter, Joe, Carl, Dr. Hartman, Quagmire, Seamus, and Mayor Adam West.

Tom is arrested by the police and the guests prepare to leave, Lois goes to comfort Tom's co-anchor, Diane Simmons, only to intuitively realize she is the true murderer. Diane reveals that she had dated Woods until he dumped her upon her fortieth birthday, around which Tom arranged her to be replaced on the Channel 5 News. Seeking revenge, Diane bribed Priscilla to manipulate Woods into throwing the dinner party so she could murder Woods and frame Tom for the crime, but was forced to kill the other guests after her plan went awry upon Stephanie's accidental death. Diane then attempts to silence Lois, only to be shot down with a suppressed sniper rifle by Stewie, who proclaims if anyone were to kill Lois, he would be the one to do it.