New York, Jan 17 - Hollywood star Johnny Depp says he understands the madness of his 'Alice in Wonderland' character and finds it 'fascinating'.

The actor, who plays the Mad Hatter in director Tim Burton's fantasy-adventure 'Alice in Wonderland', said he was dragged into his character's odd sense of reality whilst researching Lewis Carroll's classic story, reports hollywoodpulse.com.

'I started reading the book and understanding the character and the significance of the letter M. There's a moment when he says, 'I'm investigating things that begin with the letter M'. That was huge for me. Hatters were referred to as mad because of the mercury they used to use in the glue. Mercury was the M. I found that fascinating,' said the 46-year-old.