"I won't have a tiger chasing me either," Rincewind points out. "What?! It's not like I have any allies who wouldn't do the same to me! And if the enemies are chasing me, maybe they'll bother the tiger and they'll have more to worry about than catching me."
Rincewind, who thought he'd been running for considerably longer, bristles. "I did not! You, well, you did what every other teacher I've ever had did!" He's settled down to a jog now. It's much easier for conversing. "All right. I'll bite. WHY am I doing this? Aside from the fact that you'll kill me if I don't. Which is a very compelling reason," he hastens to add, "but if there's something else to it, I'd like to know."