Plutonium Princess. Under The Magic Adventure, #6

Archaeologists, Victoria Ventures and Tommy Garrison, cross the final Disneyland park off their Bucket List. In this sixth and final installment of the Under The Magic Series, the spelunking couple flies to California and checks into the Grand Californian Hotel. During an earthquake, they evacuate their hotel and stand by the pool. They watch in horror as a large crack appears in the ground and makes its way to the 'Happiest place on Earth'.
Luckily, the theme parks are spared, but the crack reached the pool and drained it. But where did the water go? Victoria and Tommy pack their cave exploring paraphernalia and rock-climbing gear and descend into the enormous crack in the Earth. Jules Verne was right, the Earth is hollow after all, and they discover the most amazing archaeological find Under The Magic!