The Coming of the Dark (http://nifflas.lpchip.nl/index.php?topic=2745.msg31398#msg31398)
Because I'd rank this as fairly impossible without foreknowledge,
After you get the eye, backtrack to where there's a red robot shooting over the ocean and 'enter' the red pipe (I did not make that clear enough at all). Also it will save you a lot of grief to know: hive, cave, desert, hive, castle, desert, cave, castle.