Brief Summary: Jin-e and Kenshin fight to the death with Kaoru's life on the line.
Although Kaoru's kidnapping has clearly angered Kenshin, he's still holding back. So Jin-e ups the ante by using his special attack, the Shinoippo on Kaoru to paralyze her lungs. The only way to break the spell is through Jin-e's death or in the unlikely event that Kaoru is able to break the spell herself (only if her will is stronger than Jin-e's).
To be brief, Kenshin kicks Jin-e's ass and it is awesome! At the crucial moment, fueled by her feelings for Kenshin, Kaoru breaks Jin-e's spell with the strength of her own will proving that she isn't just a damsel in distress. Her true strength is the strength of her convictions which is an area which Kenshin sometimes shows weakness. He's more susceptible to the temptation of a quick-and-easy kill to achieve the greatest good because he has the carnal knowledge of first hand-experience. When he falters in this fight, it is Kaoru's belief in him that ultimately brings him back. As a fighter it would be unfair to hold her to the same standard of those that survived the chaos of the Revolution. A life of theoretical knowledge and sword study isn't quite the same as wartime where a fighter's skills and spirit are tested under the greatest pressure on a daily basis.