Okay, I'm throwing my hands up - I give up, I need help.
I cross the chasm with the Orb of Thrallni; Go inside the Strange Cave. Read some warning signs go into a Portal, takes me to another small area with water and another smokey portal.
After this, I'm see some lava and am attacked by 3 Guardian Hellhounds. I kill them, and there is another smokey portal. I go in and it teleports me back to the previous cave area with water.
There is nowhere else to go, One way in and one way out. I loop between the two caves and the 3 hellhounds respawn each time. (now they are Hellound Shades)
Thank you for any help, this is the iPad version of the game.