Before Marvin dies, he is helped to get to see the big burning words. What book was this, what planet were they on, and did Adams actually say what the words said?
From Wikipedia --
"We apologise for the inconvenience." God's Final Message to His Creation, written in letters of fire on the side of the Quentulus Quazgar Mountains.
"I think," Marvin murmured at last, from deep within his corroding rattling thorax, "I feel good about it."
The lights went out in his eyes for absolutely the very last time ever.
The Quentulus Quazgar Mountains are found on the planet Preliumtarn of the famed Sevorbeupstry orbiting the Sun Zarss in Galactic Sector QQ7 Active J Gamma.