Try this incantation.

You can't resist the temptation. This seems far too interesting to ignore. Opening your mouth, you let the strange sylables flow forth, forming the unusual and jarring words.

As you speak you feel a heat growing in the pit of your stomach. It seems to course through your veins, in time with your pulse and the cadence of your speech. It begins to almost burn, nearly painful in sensation. You want to stop speaking, but for some reason you cannot. The heat, the fire, seem to be enveloping you and you're just along for the ride.

Your vision seems to go bright red for a moment, the fire burning behind your eyes, before you feel yourself smash to the floor exhausted. The impact was heavy, and you lie there, stunned for a moment, before you realize that something is wrong.

Your weight is wrong. You're heavier than you were, and you felt it when you hit the ground. You gasp slightly, looking down at yourself. You panic for a moment, realizing that you've lost a great deal of your chest. Dear lord, there's NOTHING there.

There is a moment of pinching, and you reach downward, pushing yourself absently. Yourself? Oh god, you think to yourself, I've got a COCK!

Opposition of the morning star... you think, morning star, Venus. Red star. Mars. The spell turned you into a GUY! You feel a sudden urge to race to the nearest bathroom and see what has happened to you. It's just then that you hear a sound of motion behind you. You realize that you might actually be in a little trouble, since you're in the WOMEN'S only hall...