9 6 ) ▁A ▁space ▁sh utt le ▁has ▁been ▁ground ed , ▁due ▁to ▁a ▁myster ious ▁t apping ▁sound ▁coming ▁from ▁its ▁outer ▁surface . ▁Unless ▁the ▁girls ▁can ▁figure ▁out ▁what ▁is ▁going ▁on , ▁the ▁space ▁sh utt le ▁will ▁be ▁not ▁be ▁able ▁to ▁lift - off . ▁To ▁figure ▁out ▁the ▁mystery , ▁they ▁get ▁help ▁learning ▁about ▁space ▁travel ▁through ▁the ▁U . S . ▁Space ▁Camp ▁program . ▁▁ 8 . ▁The ▁Case ▁of ▁the ▁Sh ark ▁Enc ounter ▁( 1 9 9 6 ) ▁Three ▁pir ates ▁claim ▁that ▁the ▁sh arks ▁at ▁a ▁Sea World ▁exhib it ▁are ▁singing , ▁and ▁the ▁girls ▁must ▁figure ▁out ▁where ▁the ▁strange ▁sounds ▁are ▁coming ▁from . ▁▁ 9 . ▁The ▁Case ▁of ▁the ▁Hotel ▁Who - Done - It ▁( 1 9 9 6 ) ▁The ▁girls ▁travel ▁to ▁Hawai i , ▁where ▁they ▁meet ▁a ▁hotel ▁manager ▁who ▁has ▁been ▁dealing ▁with ▁a ▁string ▁of ▁recent ▁disappear ances ▁around ▁the ▁hotel . ▁▁ 1 0 . ▁The ▁Case ▁of ▁the ▁Vol cano ▁Myst ery ▁( 1 9 9 7 ) ▁The ▁girls ▁receive ▁a ▁call ▁from ▁some ▁min ers ▁of ▁mar sh m all ows ▁that ▁a ▁snow ball - throw ing ▁mon ster ▁has ▁been ▁" ter ror izing " ▁them . ▁The ▁girls ▁eventually ▁find ▁out ▁that ▁the ▁" s now " ▁is ▁really ▁ash , ▁and ▁the ▁" mon ster " ▁is ▁actually ▁a ▁ge ologist ▁warning ▁them ▁that ▁an ▁active