River snags it out of the air without looking. (She's not showing off. She doesn't have the attention to spare for that at the moment. She's just purely focused, on the fight and her targets and the need to not let go and kill them.)

The wire is coated with rubber insulation -- useful, since neither of them has anything resembling gloves. River slips an arm through the coil for extra security and grabs tight.

There's a cluster of criminals running towards them -- or, more likely, towards the exit beyond. River sprints forward, one two three four five six steps, and drops fast to crouch on one knee.