Very interesting dream Red. The three spirits seem to symbolize death and things governed by Scorpio. The red coffin-like gems could represent Mars as the governor of Scorpio which is represented as the 'Death' card of the Tarot. Inverted Scorpio energies can mean that hidden things of an unpleasent nature can be coming to light or also the results of improperly used magickal forces.
The innocent child and the couple being taken in by the garden of malice created by the dark spirits are the same symbolically imo.
I think your dream could mean that you're concerned about someone taking an ill-advised path in relation to occult practices.
It's just a guess but I hope it helps
... --L.B.