"Danger-prone Daphne"s role was to f*** up whatever plan they concocted to catch the bad guy.
It was from Scooby-Doo that I learned an infallible law of narrative construction that has served me well ever since:
Whenever Our Heroes think up an elaborate scheme, if we are presented with an explanation of the way the scheme is supposed to work, something will go wrong so that it does not work as planned. However if the scheme is not explained ahead of time, it will work according to plan.
It’s pretty obvious why this is the case, but still, it has enabled me to predict with remarkable accuracy whether or not any scheme in any story is going to turn out to be successful.