Ritchet stared coldly into the eyes of Idun.
"Consider something," he coughed. "I'm an interdimensional being. Killing me achieves nothing. I can come back and inhabit the body of some other unfortunate soul...sure, I can't come back as anything larger than a mouse...but you wouldn't want every disease infected pest from here to the ends of the universe biting you every day, now would you?"
Ritchet had played his trump card.
"Space is big... really big. I mean, you wouldn't believe how vastly, hugely, incomprehensibly big it is. You may think it's a long way down the road to the chemist, but that's just peanuts to space." The Hitchiker's Guide to the Galaxy