Crowley turned his face into the touch, golden eyes locking on Zira's, almost saddened. "Don't talk like that. It will work," Hope was a strange emotion for a demon, almost as strange as love. But someone needed to put a bit of Good in their situation, and it was a small concession to make, to get his Angel back.
If it didn't work, it was within Crowley's power to draw Zira back to Earth; but even the minutes it would take for him to get to Hell, and speak with the proper people, would be days, weeks, to the other. He didn't want to make him suffer that, if he didn't have to.