Climbs one handed

Diana’s body moved in stops and starts as she searched for holds, making steady progress up the cliff.  Occasionally, she would grunt sharply or mutter, but she wasn’t panting or grumbling the way Alia would have been.
Just as Alia was wondering how much cardio this girl did, the cliff shook with a tremor.  Diana’s foot slipped.  They fell.
A cry escaped Alia’s lips as her heart lodged in her throat.  They jerked to a rough halt, dangling in the air, supported by nothing but Diana’s right hand jammed between rocks.  Alia could see blood trickling from somewhere between her fingers
...
Diane released something between a roar and a grunt and shoved her body upward, swinging her left arm overhead.  For a moment, Alia thought she was falling.  Then Diana’s fingers found purchase, her toes dug in, and they were wedged against rock once more.
Alia felt tension in Diana’s back, the contraction of her muscles.  They were moving again, higher and higher.  Alia didn’t risk another glance down.  She shut her eyes and, long moments later, Diana was hauling them over the top of the cliff.