What type of parent allows their sixth grader to go on these adventures?
The ones that start in their hometown are perfectly reasonable, 5th Grade and The Incredible Toy Store Adventure kinda found them while on perfectly reasonable trips and the rest...I've got nothing...On another note, there's a fanfic set in the group's teen years where Owen mentally expresses annoyance over how he and Leslie stopped being paired up on their adventures because Leslie's parents expressed concern over her safety on their excursions and requested that she go with Santiago since he's an older boy (Owen is mostly annoyed that he's also an older boy). Please note that the age difference between Leslie and Santiago is only 2 years.
It could be wholly attributed to their Weirdness Magnet: their parents have accepted that their children are going to be adventurers, ergo, they allow them to adventure.
Okay; I've got a couple about "Mystery Mansion Arcade". Firstly, since the e-mail that got the crew there was from Joni's uncle, why didn't she just call him to check (okay, okay; plot mandates it but still)? Secondly, the method under which Santiago gets captured; Owen picking up a random sandwich isn't too strange given his Big Eater tendencies and Leslie can be excused because not even someone in the Cluefinders' line of work would expect a book that comes off the shelf to trigger a trap door but seriously, Santiago? If you don't know what something is or what it does, don't pick it up!
If the pollution turns Joni and the other human captives into plants, does that mean all the plants started off as human and they too were changed into plants by the pollution?
After you complete the "Cave of Danger" activity in 6th Grade, Leslie acquires the plank using her "remote retrieval technique". Why can't she just do that at the beginning and not bother with taking out the spores?