The Delta State

The Delta state is the dimension that rifters use to store acahses while waiting 48 hours before fully Acquiring a person. Martin, Luna, Claire and Phillip go there to free them. It's said to be a very confusing dimension so humans do not like going there. Rifters seem to be the most comfortable there. It uses a person's mind and can be controlled, though this takes training.

Going Delta
This is what the group calls it when they go into the Delta state, usually if the others were not planning on the person to. This means the person(s) went into the Delta state, shown by unresposiveness. Luna, Claire, Martin and Phillip all agree that going Delta alone is not a good idea, however they do on occasion, usually to the anger of the others.

Risks
As implied, going to the Delta state has it's fair share of risks as the enviroment is prone to changing. It's not shown to be a pleasent experience for those who are not rifters. Rifters are often in the Delta state and can hunt people there, though usually they are not aquired in the Delta state. Also as people in the Delta state are unconcious in the real world, it's rare to do so in public and they need somewhere where they can stach their bodies so no one finds them while in the Delta state; also, the team will sometimes have one of the members watch over them, where they can tell if something is wrong in the Delta state and also make so no one comes in.

Being in the Delta state too long will cause a person's brain to fixate on something to counteract the chaos in the Delta state (First Contact part 2)

Enviroment
The enviroment changes depending on the person whose mind is entered. It can also be influences, sometimes by accident and it takes a lot of focus to manipulate the Delta state, Claire managed to do so in the episode "A Mix up of Genres" Also, in "Training Exercises" Brodie taught them to manipulate the Delta state.