Divergent are dangerous people who can manipulate the system. While in a simulation or dream, they are aware that what is going on isn't real, and can therefore let something dangerous happen in the simulation or dream that would kill them if it were real.

Like Beatrice, for example. (Not Bea.) A normal girl from Abnegation who felt like she didn't belong there. In fact, she didn't know where she belonged. But when she took the aptitude test to find out what faction to choose, her results turned out inconclusive.

Beatrice ended up choosing Dauntless, but will she pass all the tests and become a true Dauntless member- all while hiding the fact that she's a Divergent?