I hesitantly peep into a worn-out public school classroom on a Saturday night in Matunga, Mumbai. Inside, hunched over fourth-grader's desks, are about a dozen men having a serious discussion, but with the ease of people who have been having the same discussion every Saturday night for years. I can make out the words 'godman' , 'beard' and 'supersition' , the latter being used at regular intervals. We are at the weekly meeting of Rationalists United, a secret Mumbai group that works towards busting gurus and godmen who claim to have supernatural powers. My partner and I walk in and introduce ourselves. The men tell us that we are their first ever visitors.

The Rationalists immediately change the language from Marathi to Hindi, and the meeting's agenda from guru-busting to rookie-training. They begin by announcing that there are no miracles. India is a country teeming with swamis that claim to be able to make various objects bleed, transform and emit powders - 'miracles' that will get them scores of followers who will be milked for donations. According to the rationalists, the miracles are all just party tricks. They know because they've figured out how to replicate them.

The group uses a simple and effective method to disprove the conmen. They meet once a week to exchange information on any new gurus who have been spotted, and to figure out the science behind any new tricks on the miracle roster. Then, they walk up to the gurus' meetings and begin to replicate any tricks the man happens to be doing.

For example, the first trick I learnt was how to make lemons bleed. Traditionally, Indian culture believes that lemons can ward off evil (in the same vein as garlic and vampires), so a godman usually puts on a short performance where he pretends to purify a person, and ends the theatrics by cutting open a lemon to reveal the evil blood that he has removed. Apparently, the trick is to rub the knife with hibiscus flowers, which react with lemon juice to make a liquid that is eerily similar to blood. Enter the rationalists who quickly chop up their own bleeding lemons, and use them to start a talk about superstition and blind faith.

The session almost always ends with the upstaged guru screaming curses at them, one of the rationalists says proudly. But he is completely unruffled. "It's not like they have any powers to make them come true."

Image: The Bleeding Lemon trick. By matthijs via Creative Commons