"...in its own way" is used to mean "not according to standard ideas", or "from a certain perspective".
Perhaps the idea is not actually intriguing at face value, but the character suggests that if you change your perspective and re-think your definition of "intriguing", you may agree that yes, the idea is actually intriguing.
Here's a clearer example: "I guess he must love me, in his own way, because he looks after me." So the standard ideas about love (declarations, constant attention, etc) don't apply. However, if you consider the action of looking after the person to be a kind of "love", then you can say "in his own way".