It seems that dreaming is a passive process; dreams happen to us. In the case of nightmares, this concept may leave us feeling rather disempowered. Enter active imagination, a potent Jungian technique. The gist of it is to use your imagination to engage a dream character—a person, object, or even a feeling—by speaking to it, fantasizing about what it might do or say, or what you might do or say in relation to it. (It's best to work with whatever dream experience has the greatest emotional impact.) This kind of process can be very revealing—and healing.
Here's an example: A woman is left rattled by a dream in which a strange man threatens to attack her. During an active imagination exercise, she screws up her courage and decides to envision confronting the ominous figure. "Hello. What are you doing here?" she asks, with no small amount of trepidation. To her utter surprise, the beastly fellow suddenly transforms—into a weeping boy! The little guy is scared and wants his Mommy; he just needs to be held. Immediately her apprehension disappears. "Oh! I can handle a sad kid!" she exclaims with relief.
With some guidance, she comes to understand the intimidating figure as an expression of her own unrecognized fear, a feeling she didn't want to acknowledge. Why? She unconsciously thought that if she admitted she felt more like a trembling child than an authoritative adult she would no longer feel in control of her life. She did not validate her freaked out inner kid, so he (yes, females can have male inner children) went under cover as a terrifying man. Quite a handy device for getting the dreamer's attention, wouldn't you say? The process of active imagination allowed the woman to see her inner child despite his guise and experience feelings of great tenderness for him. Amazingly, validating her fear and giving herself some TLC turned out to be the key to regaining the sense of control and power she so desired. Who could've imagined that? Well, she could and did.