While flying, Tobias sees a shimmer in the air. A day later, he notices a flock of geese fly into a seemingly invisible wall in the air. He later tells the Animorphs, and they conclude it is a Yeerk ship. They find it decloaked over a lake, which has been guarded by Hork-Bajir and human Controllers. The Yeerks plan to suck up water from the lake and bring it to the Yeerk Pool ship. The Animorphs (minus Tobias) plan to morph fish and get sucked up into the Truck ship, then decloak it over a city to show the public about the Yeerks. The first step works, and the fish-morphed Animorphs get sucked into a water tank. However, they are stuck, and the only way out is a grate at the top.