In tunnel 2 jump across the first gap from the start and keep going right, running from the flying slig. Drop and roll continuing on to the right and fall into the area below. Roll through the narrow caves around the fan until you reach the lower right corner of the screen. Before you're tempted to pull up, climb down behind that big rock. When you land roll over to the well and jump in, and you'll appear in the background with the flying slig you're talking about. Your 6 Muds are there so lead them all to the right and chant. To get back out jump over the gap and into the well on the right.
I hope thats it
[Edit] This is in Necrum Mines, near the very beginning of the game. Are you starting the game again?