The two boys were highly surprised and fascinated. They saw fresh muddy imprints of a pair of feet. They wondered how those footmarks came there. They were surprised not to see the man who caused those footprints. They only followed them till they grew fainter and finally disappeared.
The explanation of the mystery was simple. Those were the footmarks of a brilliant but eccentric scientist Griffin. Griffin had carried out experiment after experiment to prove that human body could become transparent and invisible like a sheet of glass. He discovered certain rare drugs. He swallowed them and his body became invisible and transparent like a glass. But this invisibility was possible only when he didn't wear any clothes. If dressed up, he could lose his invisibility. He could be seen by others if he was not naked. So his invisibility became a curse for Griffin. He had to be without clothes in the chilly weather of mid-winter. This made him a homeless wanderer without clothes and without money. He had become a lawless man committing thefts and burglaries to clothe and feed himself.