You don’t react quick enough and fall down the black hole in the floor. You can feel yourself in free-fall for a few seconds and then you hit a hard surface – knocking yourself unconscious in the process.
When you eventually wake up, an indeterminate amount of time has passed and you find yourself helplessly tied up spread eagled on the ground. You also have a ball-gag in your mouth. As you attempt to break free, you start to have flashbacks of your last adventure and think to yourself, “not THIS again!”