go and tell your master that we have been charged by god with a sacred quest. if he will give us food and shelter for the night, he can join us in our quest for the holy grail. >> well, i'll ask him, i don't think he'll be very keen. he's already gone one, you see? >> what? he's already got one. are you sure he's got one? >> oh, yeah, master. >> told him he already got one. >> a clip from monty python's "the holy grail." the british troupe announced they're reuniting for a one-night show in london. >> so why have the comedy legends decided to fly again for the first time in more than 30 years? and what can we expect from this