"Ex-sensei," muttered Kakashi, under his rasping breath. "And he's not that stupid." He chanced a glance back at the teenager chasing him, and threw himself sideways. One hand slapped a brief hold on a solid oak with a palmful of chakra; he lunged for the next tree.

The chuunin kept perfect step.

Kakashi snarled something nasty under his breath and tried to move faster. His muscles sang a symphony of weary complaint. Behind one half-closed lid, Obito's eye ripped an ugly circle of pain in its borrowed socket. Kakashi faltered momentarily, attention dragged sideways, and almost lost his balance.

He caught a branch at the last second and yanked himself forwards, forcing his legs to move like he wanted. Chakra flickered in tired ripples through his coils. The chuunin was catching up.

"Go away," Kakashi snarled, refusing to look back. He risked dropping one hand for a soldier pill.