Marvin was wandering. Not a happy, joyful stroll, more a sort of morose meander. Nevertheless, he had a purpose. On the basis of the information he had gained from his limited conversation with Zaphod, Ford and Arthur, he decided to do an improbability sum. He knew where they had been due to a particle analysis test he ran on meeting them again to pass the time. He knew where he was, because he was that sort of robot. He linked his mind modem into Eddie on the Heart of Gold to assess the ship's speed, weight, improbability velocity, relative journey time in nanoseconds, molecular reabsorbtion during flight and the general mood the ship was in during the trip to Sirius. To this he added his knowledge of improbability physics, the space vector correlation, wind factors, quasi-social and semi-structural effects data from previous flights and the general mood he was in. To this he subtracted 42, divided the remainder by the square root of -l and related his answer to the floor layout of the initiative test. He knew that the total opposite of calculated position was where he wanted to go.
The room to which Marvin was heading was locked from the outside, much to the annoyance of it's occupants. They had tried everything they could think of with the candle, box of matches and blank piece of paper they had been left. Lighting the candle with the matches only lit the candle and trying to push the key out with the matches to catch on the piece of paper pushed under the door had no effect. The key was a dud anyway. Trying to burn the door down showed desperation and was doomed from the start but supplied some excuse to vent anger. The same applied to trying to kick down the door.
"There must be a logical solution," said Fenchurch.
"Why?" Asked Bolo. "There's no logical explanation as to why we ended up here, is there?"
"Well it's all very improbable," sighed Trillian. "So I imagine the men had something to do with it as they were using the Heart of Gold tonight."
"Why don't we try burning the matches and writing a note on the paper with the burnt sticks, slip it under the door and perhaps someone will see it," said Fenchurch.
"It's worth a try," said Trillian.
"No it's not," said Marvin as the door slid open to a jovial 'happy service'.
"Marvin!" Cried Trillian. She flung her arms around him. "Are we glad to see you."
"No you're not," sulked Marvin.
"We are," said Fenchurch. "We thought we'd be stuck here for days."
"How did you open the door?" Asked Trillian.
"Simple," said Marvin. "I said 'Macaroni'."
"Is that logical?" Asked Fenchurch.
"Look," started Marvin, making it perfectly clear he didn't want to. "If you had held the paper over the candle lit by the matches, then the word 'Macaroni' would have appeared."
"I take it this is the Marvin you told me about," said Bolo.
"Well it sounds like him," said Trillian. "Marvin, I thought you were, er....."
"Yes, so did I," moaned Marvin. "Come on, we've got work to do."