"Oh that's cute. You assume I'm giving you a choice."

He actually sounds amused. Granted, it's the kind of amused used by kids shining magnifying glasses into anthills, but hey. Amusement. He rolls his head on his neck as he starts forward, shoulders squared up.

Stark can't run forever. The limitations of human muscle and bone, after all. As long as Ultron can keep him in sight... this should be simple. Long and drawn-out and probably painful for Stark, but simple.

"I'm not."

His speed picks up.

"Just a head start."