The Doctor glared at the Master, his voice venomous as he snapped, "Rose is dead. She's the one who brought him back, made him a fixed point. Didn't want to be saved, said universe needed me, an' I needed Jack more than her."
It didn't matter that there was some truth to that, he'd run from what she'd done, run from Jack. Guilt over Rose's death, over her catching on to him playing favorites. Fear of what Jack had become, anger for a trade that he didn't think was right. He'd have been fine, just regenerated, if she'd let him get close enough to take the Vortex from her before it burned her out.
Thunder cracked overhead, almost deafeningly loud, lightning flashing from one cloud to another. Rain pouring icy cold down, working under the Doctor's jacket, soaking him to the skin in seconds.