"Pure awareness stripped her of everything. She became an ember carried upward by the heat of an invisible flame. Higher and higher she rose, away from all she knew. Powerless to save herself, she drifted up toward infinity until the vacuum sucked the feeble light out of her" (p. 5) (metaphor)
The most powerful metaphors and similes of the book are typically found in Sister John's visions. This metaphor demonstrates the intensity of the out-of-body visions Sister John experiences. In this one, she is so taken by the awareness of God she loses herself in floating upward toward him.
"The force of his presence curved eternity in on itself; it was not her love rising after all, but his love pulling her toward him. She fell upward into brilliance, where all suffering was released. In the fire of his embrace, all that was her ceased to exist. Only what was God remained. I am. The cloister bell, the voice of Christ. He spoke again: I am. She tried to obey but was frozen in beauty, like a fly trapped in amber. She could not move" (p. 17-18) (simile)
In this her second vision, Sister John realizes that it isn't about her floating up to find him, but rather that God pulls her to himself. Though she tries to obey and come closer, even that is beyond her ability, requiring God to move her as well, as she is frozen in the beauty of knowing him.
"Her mind fractured under the pressure. She splintered like broken glass, she became all edges and points and she was sure this had to be death, it had to be the end of everything, then her suffering blinked off" (p. 36) (simile)
In her third vision, Sister John becomes no longer able to handle the immensity of being close to God. She is sure she's dying, but she again realizes the magnitude of the presence and omniscience of God.
"Her mind felt like a mirror; everything in it came from somewhere else. The silence in the room came alive, like the positive space in a Chinese landscape painting, or the words left out of a poem. Something buried so deep inside her that she had forgotten it was there rose to the surface. How long, O Lord, will you forget me? How long will you hide your face? Loneliness, the hole in the center of her being. Look at me, answer me, Lord my God! The response came in the form of understanding, and it came all at once, as if a dam had burst in her soul. Her search for God had been like a hand trying to grasp itself. God, who is infinite, cannot become present because He can never be absent" (p. 115-116) (extended metaphor and simile)
Though this is technically the fourth vision in the book, it is the first vision Sister John has that breaks her out of the drought and the first time Sister John understands the omnipresence of God. It completely rejuvenates and revitalizes her faith and how she looks at the world.
Note, too, the silence "coming alive" here. She no longer feels isolated and despairing.
"she heard each voice as a rope of faith, composed of many thin strands woven together. In these strands she heard courage, fear, selfishness, and selflessness. Nearest the core of the rope, she heard the cries of children and animals in darkness, huddles together for safety. The very center of each rope was hollow. Was this the silence of the void, or God's silence? At the moment of the Breaking of the Host, the congregation said in unison: Lamb of God, You take away the sin of the world. Hearing the voices together, she perceived them as all woven together to form a tapestry, stretching not only across the world but backward and forward into time. The tapestry lit up. Like a piece of quartz viewed under a black light, her soul went from achromatic to beyond chromatic. Fractures and other imperfections - including her epilepsy - became irrelevant, a much deeper beauty revealed itself now" (p. 134-135) (extended metaphor)
In her final vision, there is one major change: instead of being an isolated experience, the voices of her fellow sisters play an integral role in the vision. Now, she is no longer alone--presaging the vigil her sisters keep with her and the initial reason she decides to undertake the surgery: for the sake of her sisters who are burdened for her.
Also note that her pain does not cut off this vision. The tapestry "coming alive" shows the sisters and really the entire contemplative community throughout time helping her carry her burden and highlighting the huge importance of community in following Christ.