The door behind Mark was blocked by Ivan.

He'd made Joanna bring her own bike, although she preferred riding behind Mark on his.

Dorian clumsily tumbles down behind Mark, leading to a concussion which causes her to fall into a brief coma.

Stanley sat behind Mark in the saddle, holding the reins, keeping Maggie at a slow, gentle pace.

"Ben and I." Behind Mark, entering from the hallway, appeared another big man.

Just behind Mark, Ben's voice, sounding like a rumble of distant thunder, began to swear.

He had run almost without a pause since before dawn, and he swung up behind Mark.

"Really lays it on," a voice said behind Mark.

The sun was behind Mark, shining into Ben's face, turning his helmet screen opaque and shiny.

Braden asked, having rushed in a dozen seconds behind Mark.