Malcolm's Chamber is a secret underground office, underneath the stone well in his backyard in Paradise. The well has Loric symbols on the lid.
Inside is a secret working place which contains computer equipment, papers and documents, supplies, a White Tablet given to him when he became a Greeter (which has since been taken by Number Four) , and the large skeleton of Pittacus Lore.
It is unknown exactly what the function of this office was, however it is most likely that Malcolm used it to hide all of his knowledge of the Garde. After his dad's disappearance, Sam wakes up one night at 2am and sees movement outside near the sundial, the entrance of the chamber, he makes out four or five people but they soon disappear. This occurance is yet to be explained.
Before Malcolm's disappearance he left small clues to his son Sam Goode to suggest that the well was important. When later on the run with Four and Six, Sam remembers his Dad's well and the group return to Paradise to investigate. Four and Six manage to open the well by using Sam's birthday in loric numbers. However, they are soon ambushed by Mogadorians and part of the ceiling caves in, they escape and close the well door behind them.
When Malcolm is freed from the Mogadorians at Ashwood Estates by Adamus, they travel to Paradise. Malcolm speaks with Sam's mum and finds out about the battle that took place and that Sam was presumably taken. He finds that someone has entered his secret office but deduces that it would not be mogadorians otherwise they would not have left it the way it was. Malcolm and Adamus stay there for the night and plan to travel to Dulce to find Sam.